Transmission of acknowledgement information in adaptively configured TDD communication systems

ABSTRACT

Methods and apparatus of a base station or a User Equipment (UE) in communication with each other are provided. The UE is configured by the base station for operation with an adapted Time Division Duplex (TDD) UpLink-Downlink (UL-DL) configuration. A process enabling transmission of acknowledgement information from the UE for communication in two different sets of DL Transmission Time Intervals (TTIs) is provided.

CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY

The present application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 14/204,979 filed Mar. 11, 2014 and entitled“Transmissions of Acknowledgement Information in Adaptively ConfiguredTDD Communication Systems,” which claims priority to U.S. ProvisionalPatent Application Ser. No. 61/780,227 filed Mar. 13, 2013 and entitled“Transmissions of Acknowledgement Signals in Adaptively Configured TDDCommunication Systems,” U.S. Provisional Patent Application Ser. No.61/824,855 filed May 17, 2013 and entitled “Transmission of UplinkControl Information in Adaptively Configured TDD Communication Systems,”U.S. Provisional Patent Application Ser. No. 61/877,121 filed Sep. 12,2013 and entitled “Transmission and Coding of Uplink Control Informationin Adaptive TDD Communication Systems,” and U.S. Provisional PatentApplication 61/898,269 filed Oct. 31, 2013 and entitled “Transmissionand Coding of Uplink Control Information in Adaptive TDD CommunicationSystems.” The above-identified patent documents are hereby incorporatedby reference in their entirety.

TECHNICAL FIELD

The present application relates generally to wireless communicationsand, more specifically, to transmitting acknowledgement information inadaptively configured time division duplex (TDD) communication systems.

BACKGROUND

Wireless communication has been one of the most successful innovationsin modern history. Recently, the number of subscribers to wirelesscommunication services exceeded five billion and continues to growquickly. The demand of wireless data traffic is rapidly increasing dueto the growing popularity among consumers and businesses of smart phonesand other mobile data devices, such as tablets, “note pad” computers,net books, and eBook readers. In order to meet the high growth in mobiledata traffic, improvements in radio interface efficiency and allocationof new spectrum is of paramount importance.

SUMMARY

This disclosure provides a method and apparatus for transmittingacknowledgement information signaling in adaptively configured timedivision duplex (TDD) communication systems.

In a first embodiment, a method is provided. The method includestransmitting, by a base station to a User Equipment (UE), configurationinformation for a first Time Division Duplex (TDD) UpLink-DownLink(UL-DL) configuration, a second TDD UL-DL configuration, and a third TDDUL-DL configuration. The method also includes transmitting, by the basestation to the UE in a DL or special SubFrame (SF) of the third TDDUL-DL configuration, either a Physical DL Control CHannel (PDCCH) or anEnhanced PDCCH (EPDCCH) conveying a DL Control Information (DCI) formatthat schedules to the UE either a reception of a Physical DL SharedCHannel (PDSCH) or a release of a Semi-Persistently Scheduled (SPS)PDSCH in the DL or special SF. If the DCI format is conveyed by theEPDCCH it includes an Acknowledgement Resource Offset (ARO) field. Inresponse to receiving, by the UE, the first TDD UL-DL configuration, thesecond TDD UL-DL configuration, and the third TDD UL-DL configuration,the UE determines, according to the second TDD UL-DL configuration, anUL SF to transmit acknowledgement information in response to at leastone reception of PDSCH or SPS PDSCH release in a set of DL or specialSFs of the third TDD UL-DL configuration. The UE also receives a numberof PDSCHs and SPS PDSCH release in a subset of the set of DL or specialSFs. The UE also determines acknowledgement information for the set ofDL and special SFs in response to at least the reception of the numberof PDSCHs and SPS PDSCH release in the subset of the set of DL orspecial SFs. The UE further determines a first subset of the set of DLor special SFs that are DL or special SFs in the first TDD UL-DLconfiguration for which acknowledgement information is transmitted inthe UL SF and a second subset of the set of DL or special SFs comprisingof DL or special SFs that are not in the first subset. The UE alsodetermines a first set of resources and a second set of resources in theUL SF. A resource in the first set of resources corresponds to a SF inthe subset that is in the first subset. The resource is determinedeither using a first offset if the reception is scheduled by a PDCCH orusing the ARO field and a second offset if the reception is scheduled byan EPDCCH. A resource in the second set of resources corresponds to a SFin the subset that is in the second subset. The resource is determinedusing a third offset if the reception is scheduled by a PDCCH or usingthe ARO field and the second offset if the reception is scheduled by anEPDCCH. The UE also selects, from the first set of resources or from thesecond set of resources, a resource of a physical UL control channel totransmit the acknowledgement information based on the values of theacknowledgement information. The UE further transmits, to the basestation, the acknowledgement information in the selected resource.

In a second embodiment, a method is provided. The method includestransmitting, by a base station to a User Equipment (UE), configurationinformation for a first Time Division Duplex (TDD) UpLink-DownLink(UL-DL) configuration and a second TDD UL-DL configuration. Each ULSubFrame (SF) in the second TDD UL-DL configuration is also an UL SF inthe first TDD UL-DL configuration. The method also includestransmitting, by the base station to the UE in a DL SF of the first TDDUL-DL configuration, a control channel conveying a DL ControlInformation (DCI) format that schedules a transmission by the UE of aPhysical UL Shared CHannel (PUSCH) in an UL SF of the first TDD UL-DLconfiguration and includes at least a field of binary elements. The UEcan transmit acknowledgement information in the PUSCH if the UL SF isalso an UL SF in the second TDD UL-DL configuration. If the UE cantransmit acknowledgment information in the UL SF, the field functions asa DL Assignment Index (DAD informing the UE of a number of DL or specialSFs for the UE to transmit acknowledgement information. If the UE cannottransmit acknowledgment information in the UL SF and the UE operateswith a TDD UL-DL configuration that does not have more UL SFs than DLand special SFs, the field value is always set to zero.

In a third embodiment, a method is provided. The method includestransmitting, by a base station to a User Equipment (UE), configurationinformation for a first Time Division Duplex (TDD) UpLink-DownLink(UL-DL) configuration, a second TDD UL-DL configuration, and a third TDDUL-DL configuration. The method also includes transmitting, by the basestation to the UE in a DL or special SubFrame (SF) of the third TDDUL-DL configuration, a Physical DL Control CHannel (PDCCH). The PDCCH isof a first type or of a second type and conveys a DL Control Information(DCI) format that schedules to the UE in the DL or special SF either areception of a Physical DL Shared CHannel (PDSCH) or a release of aSemi-Persistently Scheduled (SPS) PDSCH. In response to receiving, bythe UE, the first TDD UL-DL configuration, the second TDD UL-DLconfiguration, and the third TDD UL-DL configuration, the UE determines,according to the second TDD UL-DL configuration, an UL SF to transmitacknowledgement information in response to at least one reception ofPDSCH or SPS PDSCH release in a set of DL or special SFs of the thirdTDD UL-DL configuration. The UE receives a number of PDSCHs and SPSPDSCH release in a subset of the set of DL or special SFs. The UE alsodetermines acknowledgement information for the set of DL and special SFsin response at least to the reception of the number of PDSCHs and SPSPDSCH release in the subset of the set of DL or special SFs. The UEfurther determines a first subset of the set of DL or special SFs thatare DL or special SFs in the first TDD UL-DL configuration for whichacknowledgement information is transmitted in the UL SF and a secondsubset of the set of DL or special SFs comprising of DL or special SFsthat are not in the first subset. The UE transmits, to the base station,the acknowledgement information. Acknowledgement informationcorresponding to the first set of DL or special SFs and the second setof DL SFs is transmitted in the UL SF. Each SF in the subset of the oneor more DL or special SFs is either in the first set or in the secondset. The UE further transmits to the base station, the acknowledgementinformation. Acknowledgement information corresponding to DL or specialSFs in the first subset is ordered prior to acknowledgement informationcorresponding to DL SFs in the second subset if the transmission is in aPhysical UL Control CHannel (PUCCH) and wherein acknowledgementinformation is ordered according to the index of a DL or special SF inthe second TDD UL-DL configuration if the transmission is in a PhysicalUL Shared CHannel (PUSCH).

In a fourth embodiment, a base station is provided. The base stationincludes a transmitter configured to transmit, to a User Equipment (UE),signaling indicating a first Time Division Duplex (TDD) UpLink-DownLink(UL-DL) configuration, signaling indicating a second TDD UL-DLconfiguration, and signaling indicating a third TDD UL-DL configuration.The base station also includes a transmitter configured to transmit, tothe UE, either a Physical DL Control CHannel (PDCCH) or an EnhancedPDCCH (EPDCCH), in a DL or special SubFrames (SFs) of the third TDDUL-DL configuration, conveying a DL Control Information (DCI) formatthat schedules to the UE either a reception of a Physical DL SharedCHannel (PDSCH) or a release of a Semi-Persistently Scheduled (SPS)PDSCH in the DL or special SF. If the DCI format is conveyed by theEPDCCH it includes an Acknowledgement Resource Offset (ARO) field. Thebase station includes a receiver configured to receive, from the UE,acknowledgement information in a resource of a physical UL controlchannel from a first set of resources or from a second set of resources.The base station includes a processor configured to determine an UL SF,according to the second TDD UL-DL configuration, for receivingacknowledgement information for a set of DL or special SFs in the thirdTDD UL-DL configuration. The acknowledgement information is in responseto at least one transmission of PDSCH or SPS PDSCH release in the set ofDL or special SFs. The base station also includes a processor configuredto determine a first subset of the set of DL or special SFs that are DLor special SFs in the first TDD UL-DL configuration for whichacknowledgement information is transmitted in the UL SF and a secondsubset of the set of DL or special SFs comprising of DL or special SFsthat are not in the first subset. The base station further includes aprocessor configured to determine the first set of resources and thesecond set of resources in the UL SF. A resource in the first set ofresources corresponds to a SF in the first set and is determined eitherusing the first offset if the transmission is scheduled by a PDCCH orusing the ARO field and a second offset if the transmission is scheduledby an EPDCCH. A resource in the second set of resources corresponds to aSF that is in the second set and is determined using a third offset ifthe transmission is scheduled by a PDCCH or using the ARO field and thesecond offset if the transmission is scheduled by an EPDCCH.

In a fifth embodiment, a User Equipment (UE) is provided. The UEincludes a receiver configured to receive, from a base station,signaling indicating a first Time Division Duplex (TDD) UpLink-DownLink(UL-DL) configuration, signaling indicating a second TDD UL-DLconfiguration, and signaling indicating a third TDD UL-DL configuration.The UE also includes a receiver configured to receive, from the basestation, either a Physical DL Control CHannel (PDCCH) or an EnhancedPDCCH (EPDCCH), in a DL or special SubFrames (SFs) of the third TDDUL-DL configuration, conveying a DL Control Information (DCI) formatthat schedules to the UE either a reception of a Physical DL SharedCHannel (PDSCH) or a release of a Semi-Persistently Scheduled (SPS)PDSCH in the DL or special SF. If the DCI format is conveyed by theEPDCCH it includes an Acknowledgement Resource Offset (ARO) field. TheUE includes a transmitter configured to transmit, to the base station,acknowledgement information in a resource of a physical UL controlchannel from a first set of resources or from a second set of resources.The UE includes a processor configured to determine an UL SF, accordingto the second TDD UL-DL configuration, for the transmitting theacknowledgement information for a set of DL or special SFs in the thirdTDD UL-DL configuration. The acknowledgement information is in responseto at least one reception of PDSCH or SPS PDSCH release in the set of DLor special SFs. The UE also includes a processor configured to determinea first subset of the set of DL or special SFs that are DL or specialSFs in the first TDD UL-DL configuration for which acknowledgementinformation is transmitted in the UL SF and a second subset of the setof DL or special SFs comprising of DL or special SFs that are not in thefirst subset. The UE further includes a processor configured todetermine the first set of resources and the second set of resources inthe UL SF. A resource in the first set of resources corresponds to a SFin the first set and is determined either using a first offset if thereception is scheduled by a PDCCH or using the ARO field and a secondoffset if the reception is scheduled by an EPDCCH. A resource in thesecond set of resources corresponds to a SF that is in the second setand is determined using a third offset if the reception is scheduled bya PDCCH or using the ARO field and the second offset if the reception isscheduled by an EPDCCH.

In a sixth embodiment, a base station is provided. The base stationincludes a transmitter configured to transmit, to a User Equipment (UE),signaling indicating a first Time Division Duplex (TDD) UpLink-DownLink(UL-DL) configuration and signaling indicating a second TDD UL-DLconfiguration. Each UL SubFrame (SF) in the second TDD UL-DLconfiguration is also an UL SF in the first TDD UL-DL configuration. Thebase station also includes a transmitter configured to transmit, to theUE in a DL SF of the first TDD UL-DL configuration, a control channelconveying a DL Control Information (DCI) format that schedules atransmission, by the UE, of a Physical UL Shared CHannel (PUSCH) in anUL SF of the first TDD UL-DL configuration and includes at least a fieldof binary elements. The UE can include acknowledgement information inthe PUSCH if the UL SF is also an UL SF in the second TDD UL-DLconfiguration. If the UE can transmit acknowledgment information in theUL SF, the field functions as a DL Assignment Index (DAI) informing theUE of a number of DL or special SFs for the UE to transmitacknowledgement information. If the UE cannot transmit acknowledgmentinformation in the UL SF and the UE operates with a TDD UL-DLconfiguration that does not have more UL SFs than DL and special SFs,the field value is always set to zero.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system or part thereofthat controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example wireless communication network accordingto this disclosure;

FIG. 2 illustrates an example user equipment (UE) according to thisdisclosure;

FIG. 3 illustrates an example eNodeB (eNB) according to this disclosure;

FIG. 4 illustrates an example PUSCH transmission structure over aTransmission Time Interval (TTI) according to this disclosure;

FIG. 5 illustrates an example UE transmitter structure for datainformation and UCI in a PUSCH according to this disclosure;

FIG. 6 illustrates an example eNB receiver structure for datainformation and UCI in a PUSCH according to this disclosure;

FIG. 7 illustrates an example PUCCH Format 3 structure in one TTI slotfor HARQ-ACK transmission with joint coding according to thisdisclosure;

FIG. 8 illustrates an example UE transmitter block diagram for HARQ-ACKinformation using a PUCCH Format 3 according to this disclosure;

FIG. 9 illustrates an example eNB receiver block diagram for HARQ-ACKinformation using a PUCCH Format 3 according to this disclosure;

FIG. 10 illustrates an example PUCCH Format 1a/1b structure in one slotof a TTI according to this disclosure;

FIG. 11 illustrates an example transmitter structure for a PUCCH Format1a/1b according to this disclosure;

FIG. 12 illustrates an example receiver structure for a PUCCH Format1a/1b according to this disclosure;

FIG. 13 illustrates an example of different interference characteristicsin different flexible TTIs according to this disclosure;

FIG. 14 illustrates example HARQ-ACK transmissions in a same UL TTI for2 different TDD UL-DL configurations according to this disclosure;

FIG. 15 illustrates an example indexing of DL TTIs in an adapted TDDUL-DL configuration, relative to a conventional TDD UL-DL configuration,for determining PUCCH resources for respective HARQ-ACK signaltransmissions according to this disclosure;

FIG. 16 illustrates an example determination of a PUCCH resource forHARQ-ACK signal transmission using a PUCCH resource offset depending ona DL TTI index of a respective PDSCH reception in an adapted TDD UL-DLconfiguration according to this disclosure;

FIG. 17 illustrates an example implicit or explicit determination of aPUCCH resource for HARQ-ACK signaling depending on whether or not arespective DL TTI index is included in a conventional TDD UL-DLconfiguration, respectively, according to this disclosure;

FIG. 18 illustrates an example determination by a UE whether tomultiplex UCI in a PUSCH depending on an associated UL PC processaccording to this disclosure;

FIG. 19 illustrates an example determination by a UE whether tomultiplex UCI in a PUSCH depending on a respective TTI according to thisdisclosure;

FIG. 20 illustrates an example use of an UL DAI field included in a DCIformat scheduling a PUSCH transmission in a TTI depending on whether ornot a UE multiplexes HARQ-ACK in the PUSCH in the TTI according to thisdisclosure;

FIG. 21 illustrates an effective bundling window size if HARQ-ACK isonly multiplexed in a PUSCH of predetermined UL TTIs according to thisdisclosure;

FIG. 22 illustrates an example UE decision for multiplexing UCI in aPUSCH transmitted in a TTI according to a UCI type and the TTI typeaccording to this disclosure;

FIG. 23 illustrates an example multiplexing in a same PUCCH of a firstCQI corresponding to a first set of TTIs, of second CQI corresponding toa second set of TTIs, and of a single PMI corresponding to both sets ofTTIs according to this disclosure;

FIG. 24 illustrates an example UE transmitter block diagram forHARQ-ACK, P-CSI for a first set of TTIs, and P-CSI for a second set ofTTIs according to this disclosure;

FIG. 25 illustrates an example eNB receiver block diagram for HARQ-ACK,P-CSI for a first set of TTIs, and P-CSI for a second set of TTIsaccording to this disclosure;

FIG. 26 illustrates an example resource allocation for PUCCH Format 3depending on a maximum total payload according to this disclosure;

FIG. 27 illustrates an example PUCCH Format 3 transmission over 2 RBsaccording to this disclosure;

FIG. 28 illustrates an example DL or UL scheduling and HARQ-ACKtransmission for a UE operating with an adapted TDD UL-DL configurationfollowed by operation with a conventional TDD UL-DL configurationaccording to this disclosure;

FIG. 29 illustrates an example transmission of HARQ-ACK information froma UE in response to detection or absence of detection by the UE of aPDCCH intended to a group of UEs where the HARQ-ACK information isincluded with other HARQ-ACK information transmitted from the UE inresponse to PDCCH detections associated with UE-specific DL schedulingaccording to this disclosure; and

FIG. 30 illustrates an example interpretation of a field in a DCI formatscheduling a PUSCH either as an UL index or as an UL DAI by a UEconfigured to operate with an adapted TDD UL-DL configuration and withTDD UL-DL configuration 0 as the conventional TDD UL-DL configurationaccording to this disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 30, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged wireless communication system.

The following documents and standards descriptions are herebyincorporated into the present disclosure as if fully set forth herein:3GPP TS 36.211 v11.1.0, “E-UTRA, Physical channels and modulation” (REF1); 3GPP TS 36.212 v11.1.0, “E-UTRA, Multiplexing and Channel coding”(REF 2); 3GPP TS 36.213 v11.1.0, “E-UTRA, Physical Layer Procedures”(REF 3); and 3GPP TS 36.331 v11.1.0, “E-UTRA, Radio Resource Control(RRC) Protocol Specification.” (REF 4).

This disclosure relates to the adaptation of communication direction inwireless communication networks that utilize Time Division Duplex (TDD).A wireless communication network includes a DownLink (DL) that conveyssignals from transmission points (such as base stations or eNodeBs) touser equipments (UEs). The wireless communication network also includesan UpLink (UL) that conveys signals from UEs to reception points such aseNodeBs.

FIG. 1 illustrates an example wireless network 100 according to thisdisclosure. The embodiment of the wireless network 100 shown in FIG. 1is for illustration only. Other embodiments of the wireless network 100could be used without departing from the scope of this disclosure.

As shown in FIG. 1, the wireless network 100 includes an eNodeB (eNB)101, an eNB 102, and an eNB 103. The eNB 101 communicates with the eNB102 and the eNB 103. The eNB 101 also communicates with at least oneInternet Protocol (IP) network 130, such as the Internet, a proprietaryIP network, or other data network.

Depending on the network type, other well-known terms may be usedinstead of “eNodeB” or “eNB,” such as “base station” or “access point.”For the sake of convenience, the terms “eNodeB” and “eNB” are used inthis patent document to refer to network infrastructure components thatprovide wireless access to remote terminals. Also, depending on thenetwork type, other well-known terms may be used instead of “userequipment” or “UE,” such as “mobile station,” “subscriber station,”“remote terminal,” “wireless terminal,” or “user device.” For the sakeof convenience, the terms “user equipment” and “UE” are used in thispatent document to refer to remote wireless equipment that wirelesslyaccesses an eNB, whether the UE is a mobile device (such as a mobiletelephone or smartphone) or is normally considered a stationary device(such as a desktop computer or vending machine).

The eNB 102 provides wireless broadband access to the network 130 for afirst plurality of user equipments (UEs) within a coverage area 120 ofthe eNB 102. The first plurality of UEs includes a UE 111, which may belocated in a small business (SB); a UE 112, which may be located in anenterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); aUE 114, which may be located in a first residence (R); a UE 115, whichmay be located in a second residence (R); and a UE 116, which may be amobile device (M) like a cell phone, a wireless laptop, a wireless PDA,or the like. The eNB 103 provides wireless broadband access to thenetwork 130 for a second plurality of UEs within a coverage area 125 ofthe eNB 103. The second plurality of UEs includes the UE 115 and the UE116. In some embodiments, one or more of the eNBs 101-103 maycommunicate with each other and with the UEs 111-116 using 5G, LTE,LTE-A, WiMAX, or other advanced wireless communication techniques.

Dotted lines show the approximate extents of the coverage areas 120 and125, which are shown as approximately circular for the purposes ofillustration and explanation only. It should be clearly understood thatthe coverage areas associated with eNBs, such as the coverage areas 120and 125, may have other shapes, including irregular shapes, dependingupon the configuration of the eNBs and variations in the radioenvironment associated with natural and man-made obstructions.

As described in more detail below, various components of the network 100(such as the eNBs 101-103 and/or the UEs 111-116) support transmittingacknowledgement information signaling in the network 100, which canutilize TDD.

Although FIG. 1 illustrates one example of a wireless network 100,various changes may be made to FIG. 1. For example, the wireless network100 could include any number of eNBs and any number of UEs in anysuitable arrangement. Also, the eNB 101 could communicate directly withany number of UEs and provide those UEs with wireless broadband accessto the network 130. Similarly, each eNB 102-103 could communicatedirectly with the network 130 and provide UEs with direct wirelessbroadband access to the network 130. Further, the eNB 101, 102, and/or103 could provide access to other or additional external networks, suchas external telephone networks or other types of data networks.

FIG. 2 illustrates an example UE 114 according to this disclosure. Theembodiment of the UE 114 shown in FIG. 2 is for illustration only, andthe other UEs in FIG. 1 could have the same or similar configuration.However, UEs come in a wide variety of configurations, and FIG. 2 doesnot limit the scope of this disclosure to any particular implementationof a UE.

As shown in FIG. 2, the UE 114 includes an antenna 205, a radiofrequency (RF) transceiver 210, transmit (TX) processing circuitry 215,a microphone 220, and receive (RX) processing circuitry 225. The UE 114also includes a speaker 230, a main processor 240, an input/output (I/O)interface (IF) 245, a keypad 250, a display 255, and a memory 260. Thememory 260 includes a basic operating system (OS) program 261 and one ormore applications 262.

The RF transceiver 210 receives, from the antenna 205, an incoming RFsignal transmitted by an eNB or another UE. The RF transceiver 210down-converts the incoming RF signal to generate an intermediatefrequency (IF) or baseband signal. The IF or baseband signal is sent tothe RX processing circuitry 225, which generates a processed basebandsignal by filtering, decoding, and/or digitizing the baseband or IFsignal. The RX processing circuitry 225 transmits the processed basebandsignal to the speaker 230 (such as for voice data) or to the mainprocessor 240 for further processing (such as for web browsing data).

The TX processing circuitry 215 receives analog or digital voice datafrom the microphone 220 or other outgoing baseband data (such as webdata, e-mail, or interactive video game data) from the main processor240. The TX processing circuitry 215 encodes, multiplexes, and/ordigitizes the outgoing baseband data to generate a processed baseband orIF signal. The RF transceiver 210 receives the outgoing processedbaseband or IF signal from the TX processing circuitry 215 andup-converts the baseband or IF signal to an RF signal that istransmitted via the antenna 205.

The main processor 240 can include one or more processors or otherprocessing devices and can execute the basic OS program 261 stored inthe memory 260 in order to control the overall operation of the UE 114.For example, the main processor 240 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceiver 210, the RX processing circuitry 225, and the TXprocessing circuitry 215 in accordance with well-known principles. Insome embodiments, the main processor 240 includes at least onemicroprocessor or microcontroller.

The main processor 240 is also capable of executing other processes andprograms resident in the memory 260. The main processor 240 can movedata into or out of the memory 260 as required by an executing processsuch as operations in support of transmitting acknowledgement signals inadaptively configured time division duplex (TDD) communication systems.In some embodiments, the main processor 240 is configured to execute theapplications 262 based on the OS program 261 or in response to signalsreceived from eNBs, other UEs, or an operator. The main processor 240 isalso coupled to the I/O interface 245, which provides the UE 114 withthe ability to connect to other devices such as laptop computers andhandheld computers. The I/O interface 245 is the communication pathbetween these accessories and the main processor 240.

The main processor 240 is also coupled to the keypad 250 and the displayunit 255. The operator of the UE 114 can use the keypad 250 to enterdata into the UE 114. The display 255 may be a liquid crystal display orother display capable of rendering text and/or at least limitedgraphics, such as from web sites. The display 255 could also represent atouchscreen.

The memory 260 is coupled to the main processor 240. Part of the memory260 could include a random access memory (RAM), and another part of thememory 260 could include a Flash memory or other read-only memory (ROM).

As described in more detail below, the transmit and receive paths of theUE 114 (implemented using the RF transceiver 210, TX processingcircuitry 215, and/or RX processing circuitry 225) support downlinksignaling for uplink and downlink adaptation in adaptively configuredTDD systems.

Although FIG. 2 illustrates one example of UE 114, various changes maybe made to FIG. 2. For example, various components in FIG. 2 could becombined, further subdivided, or omitted and additional components couldbe added according to particular needs. As a particular example, themain processor 240 could be divided into multiple processors, such asone or more central processing units (CPUs) and one or more graphicsprocessing units (GPUs). Also, while FIG. 2 illustrates the UE 114configured as a mobile telephone or smartphone, UEs could be configuredto operate as other types of mobile or stationary devices. In addition,various components in FIG. 2 could be replicated, such as when differentRF components are used to communicate with the eNBs 101-103 and withother UEs.

FIG. 3 illustrates an example eNB 102 according to this disclosure. Theembodiment of the eNB 102 shown in FIG. 3 is for illustration only, andother eNBs of FIG. 1 could have the same or similar configuration.However, eNBs come in a wide variety of configurations, and FIG. 3 doesnot limit the scope of this disclosure to any particular implementationof an eNB.

As shown in FIG. 3, the eNB 102 includes multiple antennas 305 a-305 n,multiple RF transceivers 310 a-310 n, transmit (TX) processing circuitry315, and receive (RX) processing circuitry 320. The eNB 102 alsoincludes a controller/processor 325, a memory 330, and a backhaul ornetwork interface 335.

The RF transceivers 310 a-310 n receive, from the antennas 305 a-305 n,incoming RF signals, such as signals transmitted by UEs or other eNBs.The RF transceivers 310 a-310 n down-convert the incoming RF signals togenerate IF or baseband signals. The IF or baseband signals are sent tothe RX processing circuitry 320, which generates processed basebandsignals by filtering, decoding, and/or digitizing the baseband or IFsignals. The RX processing circuitry 320 transmits the processedbaseband signals to the controller/processor 325 for further processing.

The TX processing circuitry 315 receives analog or digital data (such asvoice data, web data, e-mail, or interactive video game data) from thecontroller/processor 325. The TX processing circuitry 315 encodes,multiplexes, and/or digitizes the outgoing baseband data to generateprocessed baseband or IF signals. The RF transceivers 310 a-310 nreceive the outgoing processed baseband or IF signals from the TXprocessing circuitry 315 and up-converts the baseband or IF signals toRF signals that are transmitted via the antennas 305 a-305 n.

The controller/processor 325 can include one or more processors or otherprocessing devices that control the overall operation of the eNB 102.For example, the controller/processor 325 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceivers 310 a-310 n, the RX processing circuitry 320, andthe TX processing circuitry 315 in accordance with well-knownprinciples. The controller/processor 325 could support additionalfunctions as well, such as more advanced wireless communicationfunctions. For instance, the controller/processor 325 could support beamforming or directional routing operations in which outgoing signals frommultiple antennas 305 a-305 n are weighted differently to effectivelysteer the outgoing signals in a desired direction. Any of a wide varietyof other functions could be supported in the eNB 102 by thecontroller/processor 325. In some embodiments, the controller/processor325 includes at least one microprocessor or microcontroller.

The controller/processor 325 is also capable of executing programs andother processes resident in the memory 330, such as a basic OS andoperations in support of providing channel state information forscheduling downlink transmissions in adaptively configured time divisionduplex (TDD) communication systems. The controller/processor 325 canmove data into or out of the memory 330 as required by an executingprocess.

The controller/processor 325 is also coupled to the backhaul or networkinterface 335. The backhaul or network interface 335 allows the eNB 102to communicate with other devices or systems over a backhaul connectionor over a network. The interface 335 could support communications overany suitable wired or wireless connection(s). For example, when the eNB102 is implemented as part of a cellular communication system (such asone supporting 5G, LTE, or LTE-A), the interface 335 could allow the eNB102 to communicate with other eNBs over a wired or wireless backhaulconnection. When the eNB 102 is implemented as an access point, theinterface 335 could allow the eNB 102 to communicate over a wired orwireless local area network or over a wired or wireless connection to alarger network (such as the Internet). The interface 335 includes anysuitable structure supporting communications over a wired or wirelessconnection, such as an Ethernet or RF transceiver.

The memory 330 is coupled to the controller/processor 325. Part of thememory 330 could include a RAM, and another part of the memory 330 couldinclude a Flash memory or other ROM.

As described in more detail below, the transmit and receive paths of theeNB 102 (implemented using the RF transceivers 310 a-310 n, TXprocessing circuitry 315, and/or RX processing circuitry 320) supportdownlink signaling for uplink and downlink adaptation in adaptivelyconfigured TDD systems.

Although FIG. 3 illustrates one example of an eNB 102, various changesmay be made to FIG. 3. For example, the eNB 102 could include any numberof each component shown in FIG. 3. As a particular example, an accesspoint could include a number of interfaces 335, and thecontroller/processor 325 could support routing functions to route databetween different network addresses. As another particular example,while shown as including a single instance of TX processing circuitry315 and a single instance of RX processing circuitry 320, the eNB 102could include multiple instances of each (such as one per RFtransceiver).

In some wireless networks, DL signals include data signals conveyinginformation content, control signals conveying DL Control Information(DCI), and Reference Signals (RS). An eNB transmits data informationthrough respective Physical DL Shared CHannels (PDSCHs). An eNBtransmits DCI over Physical DL Control CHannels (PDCCHs) or EnhancedPDCCHs (EPDCCHs). A PDCCH is transmitted over one or more ControlChannel Elements (CCEs) while an EPDCCH is transmitted over ECCEs (seealso REF 1). An eNB, such as eNB 102, transmits one or more of multipletypes of RS including a UE-Common RS (CRS), a Channel State InformationRS (CSI-RS), and a DeModulation RS (DMRS). A CRS is effectivelytransmitted over an entire DL BandWidth (BW) and can be used by UEs,such as UE 114, to demodulate PDSCH or PDCCH, or to performmeasurements. eNB 102 also can transmit CSI-RS with a smaller density inthe time and/or frequency domain than a CRS. DMRS is transmitted only ina BW of a respective PDSCH or PDCCH and UE 114 can use a DMRS tocoherently demodulate information in a PDSCH or EPDCCH (see also REF 1).

In some wireless networks, UL signals can include data signals conveyinginformation content, control signals conveying UL Control Information(UCI), and RS. UE 114 transmits data information or UCI through arespective Physical UL Shared CHannel (PUSCH) or a Physical UL ControlCHannel (PUCCH). If UE 114 transmits data information and UCI in a sameTransmission Time Interval (TTI), UE 114 can multiplex both in a PUSCH.UCI includes Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK)information, indicating correct (ACK) or incorrect (NACK) detection ofdata Transport Blocks (TBs) in a PDSCH, Scheduling Request (SR)indicating whether UE 114 has data in its buffer, and Channel StateInformation (CSI) enabling eNB 102 to select appropriate parameters forPDSCH or PDCCH transmissions to UE 114. If UE 114 fails to detect aPDCCH scheduling a PDSCH, UE 114 can indicate this using a HARQ-ACKstate referred to as DTX. A DTX and a NACK can often be mapped on a samevalue (NACK/DTX value, see also REF 3). UL RS includes DMRS and SoundingRS (SRS). DMRS is transmitted only in a BW of a respective PUSCH orPUCCH. eNB 102 can use a DMRS for coherent demodulation of informationin a PUSCH or PUCCH. SRS is transmitted by UE 114 to provide eNB 102with an UL CSI.

CSI transmission can be periodic (P-CSI) in a PUCCH with parametersconfigured to UE 114 by higher layer signaling, such as for exampleRadio Resource Control (RRC) signaling, or aperiodic (A-CSI) in a PUSCHas triggered by an A-CSI request field included in a DCI format conveyedby a PDCCH scheduling the PUSCH (see also REF 2). DMRS is transmittedonly in a BW of a respective PUSCH or PUCCH and eNB 102 can use a DMRSto demodulate information in a PUSCH or PUCCH. SRS is transmitted by UE114 in order to provide eNB 102 with an UL CSI. SRS transmission from UE114 can be periodic (P-SRS) at predetermined instances with transmissionparameters configured to UE 114 by higher layer signaling or it can beaperiodic (A-SRS) as triggered by a DCI format conveyed by a PDCCHscheduling PUSCH or PDSCH (see also REF 2).

A CSI report from UE 114 includes a Channel Quality Indicator (CQI) andthe CSI report can also include a Precoding Matrix Indicator (PMI). TheCQI indicates to eNB 102 a Modulation and Coding Scheme (MCS) for aPDSCH transmission to UE 114. The PMI indicates a combining of a PDSCHtransmission from multiple eNB antenna ports in accordance with aMultiple Input Multiple Output (MIMO) transmission method. An RI reportfrom UE 114 provides information to a serving eNB for a number ofspatial layers that can be supported for a PDSCH. TABLE 1 indicatesexemplary values for a 4-bit CQI (16 index values) transmitted in aPUCCH (see also REF 3). TABLE 1A indicates a mapping for an MCS field,I_(MCS), in a DCI format scheduling a PDSCH to a modulation order(Q_(m)) and a Transport Block Size (TBS) index, I_(TBS) for datatransmission in the PDSCH. When UE 114 experiences a highSignal-to-Noise and Interference Ratio (SINR), it can be configured byeNB 102 a CQI Table having 16 index values, similar to TABLE 1, and aModulation and TBS index Table, similar to TABLE 1A, but also includinguse of 256QAM modulation to support higher values for spectralefficiency.

TABLE 1 4-bit CQI Table CQI index Modulation code rate × 1024 efficiency0 out of range 1 QPSK 78 0.1523 2 QPSK 120 0.2344 3 QPSK 193 0.3770 4QPSK 308 0.6016 5 QPSK 449 0.8770 6 QPSK 602 1.1758 7 16QAM 378 1.4766 816QAM 490 1.9141 9 16QAM 616 2.4063 10 64QAM 466 2.7305 11 64QAM 5673.3223 12 64QAM 666 3.9023 13 64QAM 772 4.5234 14 64QAM 873 5.1152 1564QAM 948 5.5547

TABLE 1A Modulation and TBS index table for PDSCH MCS Index ModulationOrder TBS Index I_(MCS) Q_(m) I_(TBS) 0 2 0 1 2 1 2 2 2 3 2 3 4 2 4 5 25 6 2 6 7 2 7 8 2 8 9 2 9 10 4 9 11 4 10 12 4 11 13 4 12 14 4 13 15 4 1416 4 15 17 6 15 18 6 16 19 6 17 20 6 18 21 6 19 22 6 20 23 6 21 24 6 2225 6 23 26 6 24 27 6 25 28 6 26 29 2 reserved 30 4 31 6

A DMRS or SRS transmission can be through a transmission of a respectiveZadoff-Chu (ZC) sequence (see also REF 1). Different CSs of a ZCsequence can provide orthogonal ZC sequences and can be allocated todifferent UEs to achieve orthogonal multiplexing of respective HARQ-ACKsignals and RS in a same PRB. Such orthogonal multiplexing can also bein the time domain using Orthogonal Covering Codes (OCC). In thismanner, as is subsequently described, a PUCCH multiplexing capacity perRB is increased by a factor of 3 (determined by the OCC with the smallerlength). A PUCCH resource n_(PUCCH) in a RB for HARQ-ACK signal or DMRStransmission is defined by a pair of an OCC n_(oc) and a CS α. If allresources within a PUCCH RB are used, resources in an immediately nextRB can be used.

A PUSCH or a PUCCH transmission power is determined so that anassociated signal is received with a desired SINR at eNB 102 whilecontrolling a respective interference to neighboring cells therebyachieving a reception reliability target and ensuring proper networkoperation. UL Power Control (PC) includes Open-Loop Power Control (OLPC)with cell-specific and UE-specific parameters and Closed Loop PowerControl (CLPC) corrections provided by eNB 102 through TransmissionPower Control (TPC) commands (see also REF 3). If a PUSCH transmissionis scheduled by a PDCCH, a TPC command is included in a respective DCIformat. TPC commands can also be provided by a separate PDCCH conveyinga DCI format 3 or a DCI format 3A, jointly referred to as DCI format3/3A, providing TPC commands to a group of UEs. A DCI format includesCyclic Redundancy Check (CRC) bits and UE 114 identifies a DCI formattype from a respective Radio Network Temporary Identifier (RNTI) used toscramble the CRC bits. For DCI format 3/3A, a RNTI is a TPC-RNTI UE 114is configured by higher layer signaling. For a DCI format scheduling aPUSCH transmission from UE 114 or a PDSCH transmission to UE 114, a RNTIis a Cell RNTI (C-RNTI). Additional RNTI types also exist. A power of aSRS transmission follows a power of a PUSCH transmission power.

FIG. 4 illustrates an example PUSCH transmission structure over a TTIaccording to this disclosure. The embodiment of the PUSCH transmissionstructure 400 over a TTI shown in FIG. 4 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

As shown in FIG. 4, a TTI corresponds to one subframe 410 that includestwo slots. Each slot 420 includes N_(symb) ^(UL) symbols 430 fortransmitting data information, UCI, or RS. Some TTI symbols in each slotare used for transmitting DMRS 440. A transmission BW includes frequencyresource units that are referred to as Resource Blocks (RBs). Each RBincludes N_(sc) ^(RB) sub-carriers, or Resource Elements (REs), and UE114 is allocated M_(PUSCH) RBs 450 for a total of M_(sc)^(PUSCH)=M_(PUSCH)·N_(sc) ^(RB) REs for a PUSCH transmission BW. Thelast TTI symbol may be used to multiplex SRS transmissions 460 from oneor more UEs. A number of TTI symbols available for data/UCI/DMRStransmission is N_(symb) ^(PUSCH)=2·(N_(symb) ^(UL)−1)−N_(SRS), whereN_(SRS)=1 if a last TTI symbol is used to transmit SRS and N_(SRS)=0otherwise.

FIG. 5 illustrates an example UE transmitter structure for datainformation and UCI in a PUSCH. The embodiment of the UE transmitter 500shown in FIG. 5 is for illustration only. Other embodiments could beused without departing from the scope of the present disclosure. Incertain embodiments, transmitter 500 is located within UE 114.

As shown in FIG. 5, coded CSI symbols 205 and coded data symbols 510 aremultiplexed by multiplexer 520. Coded HARQ-ACK symbols are then insertedby multiplexer 530 by puncturing data symbols and/or CSI symbols. Atransmission of coded RI symbols is similar to one for coded HARQ-ACKsymbols (not shown). The Discrete Fourier Transform (DFT) is obtained byDFT unit 540, REs 550 corresponding to a PUSCH transmission BW areselected by selector 555, an Inverse Fast Fourier Transform (IFFT) isperformed by IFFT unit 560, an output is filtered and by filter 570 andapplied a certain power by Power Amplifier (PA) 580 and a signal is thentransmitted 590. For brevity, additional transmitter circuitry such asdigital-to-analog converter, filters, amplifiers, and transmitterantennas as well as encoders and modulators for data symbols and UCIsymbols are omitted for brevity.

FIG. 6 illustrates an example eNB receiver structure for datainformation and UCI in a PUSCH. The embodiment of the eNB receiver 600shown in FIG. 6 is for illustration only. Other embodiments could beused without departing from the scope of the present disclosure. Incertain embodiments, eNB receiver 600 is located within eNB 102.

As shown in FIG. 6, a received signal 610 is filtered by filter 620, aFast Fourier Transform (FFT) is applied by FFT unit 630, a selector unit640 selects REs 650 used by a transmitter, an Inverse DFT (IDFT) unitapplies an IDFT 660, a de-multiplexer 670 extracts coded HARQ-ACKsymbols and places erasures in corresponding REs for data symbols andCSI symbols and finally another de-multiplexer 680 separates coded datasymbols 690 and coded CSI symbols 695. A reception of coded RI symbolsis similar to one for coded HARQ-ACK symbols (not shown). Additionalreceiver circuitry such as a channel estimator, demodulators anddecoders for data and UCI symbols are not shown for brevity.

For HARQ-ACK transmission in a PUCCH, or for a joint HARQ-ACK and P-CSItransmission in a PUCCH, a payload of O_(HARQ-ACK) HARQ-ACK bits or apayload of O_(HARQ-ACK) HARQ-ACK bits and O_(P-CSI) bits can be encodedusing, for example, a block code. A corresponding PUCCH format isreferred to as PUCCH Format 3. Considering for brevity in the followingonly the case of HARQ-ACK bits, the block code can be a (32,O_(HARQ-ACK)) Reed-Mueller (RM) code (also see REF 2). For a FrequencyDivision Duplex (FDD) system, one or two HARQ-ACK bits can also betransmitted using PUCCH Format 1a or PUCCH Format 1b, respectively,while for a Time Division Duplex (TDD) system up to four HARQ-ACK bitscan be transmitted using PUCCH Format 1b with resource multiplexing (seealso REF 3).

FIG. 7 illustrates an example PUCCH Format 3 structure in one TTI slotfor HARQ-ACK transmission with joint coding according to thisdisclosure. The embodiment of the transmitter 700 shown in FIG. 7 is forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

As shown in FIG. 7, after encoding and modulation using respectively,for example, a (32, O_(HARQ-ACK)) RM code punctured to a (24,O_(HARQ-ACK)) RM code and Quaternary Phase Shift Keying (QPSK)modulation (not shown for brevity), a set of same HARQ-ACK bits 710 ismultiplied 720 with elements of an OCC 730 and is subsequently DFTprecoded 740. For example, for 5 symbols per slot carrying HARQ-ACKbits, the OCC has length 5 {OCC(0), OCC(1), OCC(2), OCC(3), OCC(4)} andcan be either of {1, 1, 1, 1, 1}, or {1, exp(j2π/5), exp(j4π/5),exp(j6π/5), exp(j8π/5)}, or {1, exp(j4π/5), exp(j8π/5), exp(j2π/5),exp(j6π/5)}, or {1, exp(j6π/5), exp(j2π/5), exp(j8π/5), exp(j4π/5)}, or{1, exp(j8π/5), exp(j6π/5), exp(j4π/5), exp(j2π/5)}. The output ispassed through an IFFT 750 and it is then mapped to a TTI symbol 760. Asthe previous operations are linear, their relative order may beinter-changed. A PUCCH is transmitted in one RB over one TTI.Consequently, 24 encoded HARQ-ACK bits are transmitted in each slot andthey are mapped to 12 QPSK symbols. The same or different HARQ-ACK bitsmay be transmitted in the second slot of a TTI. In addition to HARQ-ACKsignals, RS are transmitted in each slot to enable coherent demodulationof HARQ-ACK signals. A RS is constructed from a length-12 ZC sequence770 that is passed through an IFFT 780 and mapped to another TTI symbol790. Multiplexing of RS from different UE is achieved by using differentCSs of a same ZC sequence.

Although the PUCCH Format 3 structure in FIG. 7 can support HARQ-ACKpayloads larger than a few bits, it requires large overhead as HARQ-ACKsignal transmissions from a maximum of 5 UEs (as determined by the OCClength) can be accommodated per RB. Moreover, a maximum supportableHARQ-ACK payload (or HARQ-ACK and P-CSI payload) is limited to onlyabout 22 bits as a resulting code rate becomes too large for reliablereception in case of payloads larger than 22 bits. For a HARQ-ACKpayload (or HARQ-ACK and P-CSI payload) between about 12 and 21 bits, adual RM code can be used where a mapping to successive elements of a DFTcan alternate between elements from an output of a first RM code andelements from an output of a second RM code in a sequential manner (seealso REF 1).

FIG. 8 illustrates an example UE transmitter block diagram for HARQ-ACKinformation using a PUCCH Format 3 according to this disclosure. Theembodiment of the UE transmitter 800 shown in FIG. 8 is for illustrationonly. Other embodiments could be used without departing from the scopeof the present disclosure. In certain embodiments, UE transmitter 800 islocated within UE 114.

As shown in FIG. 8, HARQ-ACK information bits 805 are encoded andmodulated 810 and then multiplied 820 with an element of an OCC 825 fora respective TTI symbol. After DFT precoding 830, REs 840 of an assignedPUCCH RB are selected 850, an IFFT is performed 860 and finally a CyclicPrefix (CP) 870 and filtering 880 are applied to a transmitted signal890.

FIG. 9 illustrates an example eNB receiver block diagram for HARQ-ACKinformation using a PUCCH Format 3 according to this disclosure. Theembodiment of the eNB receiver 900 shown in FIG. 9 is for illustrationonly. Other embodiments could be used without departing from the scopeof the present disclosure. In certain embodiments, eNB receiver 900 islocated within eNB 102.

As shown in FIG. 9, a received signal 910 is filtered 920 and a CP isremoved 930. Subsequently, eNB 102 receiver applies a FFT 940, selects955 REs 950 used by UE 114 transmitter, applies an IDFT 960, multiplies970 with a OCC element 975 for a respective TTI symbol, sums the outputsfor TTI symbols conveying HARQ-ACK information over each slot 980, anddemodulates and decodes summed HARQ-ACK signals over both slots 990 of aTTI to obtain an estimate of transmitted HARQ-ACK information bits 995.

FIG. 10 illustrates an example PUCCH Format 1a/1b structure in one slotof a TTI according to this disclosure. The example of the PUCCH formatstructure 1000 shown in FIG. 10 is for illustration only. Otherembodiments could be used without departing from the scope of thepresent disclosure.

As shown in FIG. 10, HARQ-ACK bits b 1010 modulate 1020 a ZC sequence1030 using Binary Phase Shift Keying (BPSK) or QPSK modulation. Amodulated ZC sequence is transmitted after performing an IFFT 1040. A RSis transmitted through an unmodulated ZC sequence 1050.

FIG. 11 illustrates an example transmitter structure for a PUCCH Format1a/1b according to this disclosure. The embodiment of the transmitter1100 shown in FIG. 11 is for illustration only. Other embodiments couldbe used without departing from the scope of the present disclosure. Incertain embodiments, the transmitter 1100 is located within UE 114.

As shown in FIG. 11, a ZC sequence is generated in the frequency-domain1110. A first RB and a second RB are selected 1120 for transmission 1130of the ZC sequence in a first slot and in a second slot, respectively,an IFFT is performed 1140, and a CS applies to the output 1150 that isthen filtered 1160 and transmitted 1170.

FIG. 12 illustrates an example receiver structure for a PUCCH Format1a/1b according to this disclosure. The embodiment of the receiver 1200shown in FIG. 12 is for illustration only. Other embodiments could beused without departing from the scope of the present disclosure. Incertain embodiments, receiver 1200 is located within eNB 102.

As shown in FIG. 12, a received signal 1210 is filtered 1220, a CS isrestored 1230, a FFT 1240 is applied, a first RB and a second RB 1250 ina first slot and in a second slot, respectively, are selected 1260, anda signal is correlated 1270 with a replica 1280 of a ZC sequence. Anoutput 1290 can then be passed to a channel estimation unit, such as atime-frequency interpolator, in case of the RS, or to a detection unitfor the transmitted HARQ-ACK bits.

In a TDD communication system, a communication direction in some TTIs isin the DL, and a communication direction in some other TTIs is in theUL. TABLE 2 lists indicative UL-DL configurations over a period of 10TTIs (a TTI has a duration of 1 millisecond (msec)), which is alsoreferred to as frame period. “D” denotes a DL TTI, “U” denotes a UL TTI,and “S” denotes a special TTI that includes a DL transmission fieldreferred to as DwPTS, a Guard Period (GP), and a UL transmission fieldreferred to as UpPTS. Several combinations exist for a duration of eachfield in a special TTI subject to the condition that the total durationis one TTI.

TABLE 2 TDD UL-DL configurations DL-to-UL TDD UL-DL Switch- Configu-point TTI number ration periodicity 0 1 2 3 4 5 6 7 8 9 0 5 ms D S U U UD S U U U 1 5 ms D S U U D D S U U D 2 5 ms D S U D D D S U D D 3 10 ms D S U U U D D D D D 4 10 ms  D S U U D D D D D D 5 10 ms  D S U D D D DD D D 6 5 ms D S U U U D S U U D

In a TDD system, a HARQ-ACK signal transmission from UE 114 in responseto PDSCH receptions in multiple DL TTIs may be transmitted in a same ULTTI. A number M of DL TTIs for which associated HARQ-ACK signaltransmissions from UEs are in a same UL TTI is referred to as a bundlingwindow of size M. A PUCCH resource determination can depend on whether adownlink control channel scheduling a PDSCH or a release of aSemi-Persistently Scheduled (SPS) PDSCH is a PDCCH one or an EPDCCH one(see also REF 3). TABLE 3 indicates DL TTIs n−k, where k∈K, for which anHARQ-ACK signal transmission is in UL TTI n.

TABLE 3 Downlink association set index K: {k₀, k₁, . . . k_(M−1)} TDDUL-DL Configu- TTI n ration 0 1 2 3 4 5 6 7 8 9 0 — — 6 — 4 — — 6 — 4 1— — 7, 6 4 — — — 7, 6 4 — 2 — — 8, 7, — — — — 8, 7, — — 4, 6 4, 6 3 — —7, 6, 6, 5 5, 4 — — — — — 11 4 — — 12, 8, 6, 5, — — — — — — 7, 11 4, 7 5— — 13, 12, — — — — — — — 9, 8, 7, 5, 4, 11, 6 6 — — 7 7 5 — — 7 7 —

In case of EPDCCH, a determination of a PUCCH resource n_(PUCCH) for aHARQ-ACK signal transmission from a first UE antenna port, in responseto a detection of a respective EPDCCH in TTI m, can be based on Equation1 (see also REF 3)

$\begin{matrix}{n_{PUCCH} = {n_{{ECCE},{n - k_{m}}} + {\sum\limits_{{i\; 1} = 0}^{m - 1}\; N_{{ECCE},{n - k_{i\; 1}}}} + {f({ARO})} + N_{PUCCH}^{({e\; 1})}}} & (1)\end{matrix}$In Equation 1, n_(CCE,m) is a lowest ECCE index of a EPDCCH scheduling arespective PDSCH or a SPS PDSCH release in TTI m, where 0≤m≤M−1,N_(ECCE,n−k) _(i1) is a total number of ECCEs in TTI n−k_(m), N_(PUCCH)^((e1)) is an offset informed to UE 114 through higher layer signalingby eNB 102, and f(ARO) is a function of a Acknowledgement ResourceOffset (ARO) field, including of 2 bits, in a DCI format conveyed by aEPDCCH. For simplicity, an equation for a PUCCH resource determinationis not described (see also REF 3).

In case of PDCCH on DL TTI n−k_(m), a PUCCH Format 1a/1b resourcen_(PUCCH) from a first UE antenna port is determined as in Equation 1a(see also REF 3)n _(PUCCH)=(M−m−1)·N _(c) +m·N _(c+1) +n _(CCE,n−k) _(m) +N _(PUCCH)⁽¹⁾  (1a)In Equation 1a, n_(CCE,n−k) _(m) is a lowest CCE index of a PDCCHscheduling a respective PDSCH or a SPS PDSCH release in TTI n−k_(m),where 0≤m≤M−1, N_(c)=max{0, └[N_(RB) ^(DL)·(N_(sc) ^(RB)·c−4)]/36┘}where └ ┘ is the ‘floor’ function that rounds a number to itsimmediately lower integer, c is a value from {0, 1, 2, 3} makingN_(c)≤n_(CCE)<N_(c+1), N_(RB) ^(DL) is a number of RBs in a DL operatingbandwidth, and N_(PUCCH) ⁽¹⁾ is an offset informed to UE 114 throughsignaling of a System Information Block (SIB) by eNB 102 (see also REF3).

The TDD UL-DL configurations in TABLE 2 provide 40% and 90% of DL TTIsper frame to be DL TTIs (and the remaining to be UL TTIs). Despite thisflexibility, a semi-static TDD UL-DL configuration that can be updatedevery 640 msec or less frequently by SIB signaling or, in case of DLCarrier Aggregation and a secondary cell by RRC signaling (see also REF3and REF 4), may not match well with short-term data traffic conditions.For the remaining of this disclosure, such a TDD UL-DL configurationwill be referred to as a conventional (or non-adapted) TDD UL-DLconfiguration and it is assumed to be used by conventional (or legacy)UEs in a cell. For this reason, a faster adaptation period of a TDDUL-DL configuration can improve system throughput, particularly for alow or moderate number of connected UEs. For example, when there is moreDL traffic than UL traffic, the TDD UL-DL configuration can be adaptedevery 10, 20, 40, or 80 msec to include more DL TTIs. Signaling forfaster adaptation of a TDD UL-DL configuration can be provided byseveral mechanisms, including signaling a DCI format in a PDCCH, MediumAccess Control (MAC) signaling, or RRC signaling.

An operating constraint in an adaptation of a TDD UL-DL configuration inways other than conventional ones is the possible existence of UEs thatcannot be aware of such adaptation. Such UEs are referred to asconventional UEs. Since conventional UEs perform measurements in DL TTIsusing a respective CRS, such DL TTIs cannot be changed to UL TTIs or tospecial TTIs by a faster adaptation of a TDD UL-DL configuration.However, an UL TTI can be changed to a DL TTI without impactingconventional UEs because eNB 102 can ensure that such UEs do nottransmit any signals in such UL TTIs. In addition, an UL TTI common toall TDD UL-DL configurations could exist to enable eNB 102 to possiblyselect this UL TTI as the only UL one. In some implementations,including all TDD UL-DL configurations in TABLE 2, this UL TTI is TTI#2.

A TTI is referred to as DL flexible TTI if the TTI is an UL TTI in aconventional TDD UL-DL configuration and is adapted to a DL TTI. A TTIis referred to as UL flexible TTI if the TTI is an UL TTI in aconventional TDD UL-DL configuration that could be adapted to a DL TTIin an adapted TDD UL-DL configuration but the TTI remains an UL TTI. ATTI is referred to as DL fixed TTI if the TTI is a DL TTI in aconventional TDD UL-DL configuration. A TTI is referred to as UL fixedTTI if the TTI is an UL TTI in a TDD UL-DL configuration a UE uses todetermine UL TTIs for transmitting HARQ-ACK information in response toPDSCH receptions. A special TTI in a conventional configuration can beadapted only to a DL TTI.

Considering the above, TABLE 4 indicates flexible TTIs (denoted by ‘F’)for each TDD UL-DL configuration in TABLE 2. Evidently, as DL TTIs in aconventional TDD UL-DL configuration cannot be changed to UL TTIs, notall TDD UL-DL configurations can be used for adaptation. For example, ifTDD UL-DL configuration 2 is the conventional one, an adaptation can beonly to TDD UL-DL configuration 5. Therefore, an indication for anadaptation for a TDD UL-DL configuration can be considered by UE 114 asinvalid if, for example, it switches a DL TTI in the conventional TDDUL-DL configuration in an UL TTI. Invalid indications can be caused, byexample, by the misdetection from UE 114 of a DCI format conveying anindication for an adapted TDD UL-DL configuration.

TABLE 4 Flexible TTIs (F) for TDD UL-DL configurations DL-to-UL TDDUL-DL Switch- Configu- point TTI number ration periodicity 0 1 2 3 4 5 67 8 9 0 5 ms D S U F F D F F F F 1 5 ms D S U F D D F F F D 2 5 ms D S UD D D F F D D 3 10 ms  D S U F F D D D D D 4 10 ms  D S U F D D D D D D5 10 ms  D S U D D D D D D D 6 5 ms D S U F F D F F F D

If eNB 102 can adapt a TDD UL-DL configuration more frequently than byRRC signaling, for example using physical layer signaling or MAC layersignaling, then flexible TTIs (which can be only UL TTIs in theconventional TDD UL-DL configuration) should not carry any periodic ULsignaling from conventional UEs as this is configured by RRC signaling.This implies that in flexible TTIs conventional UEs should not beconfigured transmissions of SRS, or CSI, or SR, or HARQ-ACK signaling inresponse to SPS PDSCH. Additionally, if a reference TDD UL-DLconfiguration is used for HARQ-ACK signaling in response to dynamicPDSCH receptions, a respective UL TTI should not be a flexible TTI.However, there is a need for UE 114 to transmit SRS in UL flexible TTIssince, as it is further subsequently discussed, the interferenceexperienced by a signal transmission from UE 114 can be different thanin UL fixed TTIs and eNB 102 needs to obtain a respective UL CSI for UE114 in a flexible TTI.

eNB 102 can signal an adapted TDD UL-DL configuration, for example,using a PDCCH that includes at least 3 bits for indicating a TDD UL-DLconfiguration from TABLE 2. The PDCCH can be transmitted either in UE114-common space or in UE 114-dedicated space and in one or morepredetermined TTIs. An adapted TDD UL-DL configuration remains validover a predetermined number of TTIs. Typically, for a PDCCH intended fora group of UEs or for all UEs in a cell, there is no HARQ-ACKtransmission from UE 114 to inform eNB 102 whether or not it detectedthe PDCCH. Consequently, for UE 114 that did not detect the PDCCHconveying an adapted TDD UL-DL configuration, communication with eNB 102is compromised as UE 114 can have an incorrect understanding of adirection (DL or UL) for a flexible TTI, thereby failing to receivePDCCH scheduling PDSCH or PUSCH transmissions when it incorrectlyassumes that a flexible TTI is an UL one and needlessly attempting todetect PDCCH when it incorrectly assumes that a flexible TTI is a DLone.

To establish a HARQ-ACK transmission timing that is independent from anadapted TDD UL-DL configuration, in order to avoid a missed detection ofa respective PDCCH affecting HARQ-ACK transmission, eNB 102 can usehigher layer signaling to inform UE 114 of a first TDD UL-DL referenceconfiguration UE 114 can assume for transmitting HARQ-ACK signals and ofa second TDD UL-DL reference configuration UE 114 can assume forreceiving HARQ-ACK signals. For example, the first TDD UL-DL referenceconfiguration can be configuration 5 while the second TDD UL-DLconfiguration can be configuration 0. Then, UE 114 always transmitsHARQ-ACK signals in TTI #2 and receives HARQ-ACK signals in TTI #0 orTTI #5.

An advantage of using TDD UL-DL configuration 5 as a referenceconfiguration for transmitting HARQ-ACK information from UE 114 andusing TDD UL-DL configuration 0 as a reference configuration forreceiving HARQ-ACK information by UE 114 is that UE 114 allows anadapted UL-DL TDD configuration to be any one from TABLE 2 subject to arestriction that TTIs indicated as DL ones in the conventional UL-DL TDDconfiguration are not changed to UL ones.

From TABLE 3, UE 114 can transmit HARQ-ACK information, in a same ULTTI, in response to PDSCH receptions in a number M of DL TTIs that isreferred to as a bundling window with size M. A consequence of usingUL-DL TDD configuration 5 as a reference one is that HARQ-ACK, P-CSI, orSR can only be transmitted in TTI #2. As TTI #2 can also be the only ULTTI where UE 114 transmits P-SRS, a multiplexing capacity of a PUCCHFormat 3 can be further constrained by the puncturing of a last TTIsymbol to accommodate P-SRS transmissions.

If UE 114 determines a HARQ-ACK payload assuming TDD UL-DL configuration5, a total HARQ-ACK payload can be 18 bits, in case UE 114 is configuredwith a PDSCH transmission mode that conveys 2 data TBs, and UE 114encodes the HARQ-ACK payload using dual RM coding (UE 114 generatesHARQ-ACK information for every DL TTI regardless of whether it receivesa DL DCI format in a DL TTI). A disadvantage of dual RM coding oversingle RM coding is a performance loss that exists when actual HARQ-ACKinformation includes less than 12 bits. Additionally, if UE 114determines a HARQ-ACK payload associated with TDD UL-DL configuration 5and also needs to multiplex P-CSI in a PUCCH Format 3 transmission, atotal combined payload can exceed 22 bits that is a maximum payload thatcan be supported by PUCCH Format 3 in one RB. Then, HARQ-ACK spatialdomain bundling needs to apply to result to a smaller HARQ-ACK payload.With HARQ-ACK spatial domain bundling, UE 114 generates an ACK only ifboth data TBs in a PDSCH are correctly received; otherwise UE 114generates a NACK. A disadvantage of HARQ-ACK spatial domain bundling isthat it results to a reduced DL throughput as UE 114 reports a NACK evenwhen UE 114 correctly receives one of two data TBs in a PDSCH. Moreover,with or without HARQ-ACK bundling, if UE 114 also multiplexes in a PUCCHFormat 3 a P-CSI for a fixed DL TTI or a P-CSI for a flexible DL TTI, aresulting total payload can be large thereby resulting to a high codingrate and worse reception reliability. The above reception reliabilityproblems are further exacerbated if UE 114 is also configured foroperation with DL Carrier Aggregation (CA) or Coordinated Multi-Point(CoMP) transmission as respective maximum payloads further increasesince HARQ-ACK and P-CSI may need to be provided for each respectivecarrier or cell.

An UL DCI format scheduling a PUSCH transmission from UE 114 includes afield that consists of two bits and functions either as an UL DownlinkAssignment Index (UL DAI) indicating to UE 114 a number of DL TTIs withrespective PDSCH transmissions or SPS release that UE 114 should includeHARQ-ACK information for in the PUSCH or, for TDD UL-DL configuration 0(as a PDSCH transmission to UE 114 can only be scheduled in a same TTIas the PUSCH transmission to UE 114) as an UL index field indicating oneor more UL TTIs for respective PUSCH transmissions (see also REF 2). Amapping of the UL DAI bits to a number of DL TTIs for UE 114 to includeHARQ-ACK information in a respective PUSCH is given in TABLE 5. For abundling window size M≥4, an UL DAI field maps to multiple numbers of DLTTIs and UE 114 can select one of them based on a number of detectedPDCCHs (see also REF 3).

TABLE 5 Value of Downlink Assignment Index (DAI) in an UL DCI format DAI(MSB, LSB) Number of TTIs with PDSCH transmission 0, 0 1 or 5 or 9 0, 12 or 6 1, 0 3 or 7 1, 1 0 or 4 or 8

One likely combination of TDD UL-DL configurations used by UE 114 forreception and transmission of HARQ-ACK information are TDD UL-DLconfiguration 0 and TDD UL-DL configuration 5, respectively, becausethey allow a maximum flexibility in selecting an adapted TDD UL-DLconfiguration. The present disclosure assumes that the conventional TDDUL-DL configuration is assumed by UE 114 for reception of HARQ-ACKinformation and a TDD UL-DL configuration is configured by eNB 102 to UE114 for determining UL subframes (and information payload) for HARQ-ACKtransmission. However, TDD UL-DL configuration 0 may not be an adaptedTDD UL-DL configuration and then, due to an absence of an UL DAI fieldin an UL DCI format, a HARQ-ACK payload UE 114 needs to multiplex in aPUSCH is determined by assuming that each DL ITT in a respectivebundling window conveys a PDSCH. When TDD UL-DL configuration 5 isassumed by UE 114 for transmitting HARQ-ACK information, a bundlingwindow size is 9 and a significant number of PUSCH resources, linearlyscaling with a total HARQ-ACK payload (see also REF 2), may beneedlessly used to transmit HARQ-ACK information as a number of PDCCHsUE 114 detects can be significantly smaller than 9.

When a PDCCH is used to convey an adapted TDD UL-DL configuration to UEsin a cell, such as for example a PDCCH conveying a DCI Format 1C (seealso REF 2) transmitted in a UE-common space, it is possible that someUEs can be in a discontinuous reception mode (DRX mode) when the PDCCHis transmitted. Consequently, such UEs will not be aware of an adaptedTDD UL-DL configuration and will have to operate using a possiblydifferent TDD UL-DL configuration. This TDD UL-DL configuration can beone configured by higher layer signaling or the conventional one andthen associated UEs can be scheduled as conventional UEs during a timeperiod for an adapted TDD UL-DL configuration. Therefore, it is possiblethat UE 114 needs to transmit in a same PUCCH or PUSCH first HARQ-ACKinformation in response to PDSCH receptions scheduled with an adaptedTDD UL-DL configuration and second HARQ-ACK information in response toPDSCH receptions scheduled with a non-adapted TDD UL-DL configuration.

A PUSCH transmission power in an UL flexible TTI can be different thanin an UL fixed TTI as interference in the former may be from acombination of DL transmissions or UL transmissions in adjacent cellswhile interference in the latter is always from UL transmissions inadjacent cells. Two separate UL PC processes can be considered for UE114; a first for use in UL fixed TTIs and in UL flexible TTIs where UE114 experiences UL-dominant interference and a second for use in ULflexible TTIs where UE 114 experiences DL-dominant interference. Each ULPC process can have its own OLPC process or its own CLPC process, orboth.

FIG. 13 illustrates an example of different interference characteristicsin different flexible TTIs according to this disclosure. The embodimentsof the interference characteristics shown in different flexible TTIsshown in FIG. 13 are for illustration only. Other embodiments could beused without departing from the scope of the present disclosure.

As shown in FIG. 13, TDD UL-DL configuration 1 is used in reference cell#1 1310, TDD UL-DL configuration 2 is used in interfering cell #2 1320,and TDD UL-DL configuration 3 is used in interfering cell #3 1330. Infixed TTI #2 in cell #1 1340, cell #2 1350, and cell #3 1360, aninterference experienced by UL transmissions is statistically same and aconventional UL PC process can apply. In flexible TTI #3 in cell #11342, an interference experienced by UL transmissions is different thanin fixed TTI #2 as flexible TTI #3 is used for DL transmissions in cell#2 1352 and for UL transmissions in cell #3 1362. Therefore, UE 114 incell #1 that is located towards cell #2 can experience significantlydifferent interference in TTI #3 than in TTI #2. In flexible TTI #7 incell #1 1344, an interference experienced by UL transmissions isdifferent than in fixed TTI #2, or flexible TTI #3, as flexible TTI #7is used for UL transmissions in cell #2 1354 and for DL transmissions incell #3 1364. Therefore, UE 114 in cell #1 that is located towards cell#3 can experience significantly different interference than aninterference experienced in TTI #2 or in TTI #3. Finally, in flexibleTTI #8 in cell #1 1346, an interference experienced by UL transmissionsis different than in fixed TTI #2, or in flexible TTI #3, or in flexibleTTI #7, as flexible TTI #8 is used for DL transmissions in both cell #21356 and cell #3 1366. Therefore, not only there exists interferencevariation between the two TTI types (fixed and flexible) but also thereexists interference variation in different flexible TTIs.

A consequence of larger interference variations in an UL flexible TTIrelative to a UL fixed TTI is that a reception reliability of data TBstransmitted in a PUSCH in a flexible UL TTI can be worse than the one ofdata TBs transmitted in a PUSCH is a fixed UL TTI. This is not a seriousissue for transmissions of data TBs that can benefit from HARQretransmissions but it is a serious issue for UCI transmissions in thePUSCH which have stricter reliability requirements and cannot benefitfor HARQ retransmissions. For UCI transmissions in the PUCCH, areference TDD UL-DL configuration can be used so that UCI in the PUCCHis always transmitted in UL fixed TTIs.

A consequence of UL-dominant interference in a flexible DL TTI is that aseparate interference measurement and CSI report is needed relative to aCSI report for fixed DL TTIs or for a flexible DL TTI with DL-dominantinterference. Therefore UE 114 should support at least two CSI processesfor channel measurements (using a CSI-RS) and for interferencemeasurements (using two respective CSI-IMs).

From TABLE 3 it is observed that when different UEs have differentunderstanding of a TDD UL-DL configuration, a respective bundling windowsize is also different and therefore an index of a same DL TTI within arespective bundling window is different. As UE 114 determines a PUCCHresource for transmitting a HARQ-ACK signal in response to a PDSCHreception from an index of a respective DL TTI in a bundling window,this can lead to a PUCCH resource collision where two or more differentUEs use a same PUCCH resource to transmit respective HARQ-ACK signals. Aremedy is for eNB 102 to configure separate PUCCH resources to be usedfor each TDD UL-DL configuration (conventional or adapted one) but thiscan significantly increase PUCCH overhead.

FIG. 14 illustrates example HARQ-ACK transmissions in a same UL TTI for2 different TDD UL-DL configurations according to this disclosure. Theembodiments of the HARQ-ACK transmissions shown in FIG. 14 are forillustration only. Other embodiments could be used without departingfrom the scope of the present disclosure.

As shown in FIG. 14, TDD UL-DL configuration 1 (bundling window size ofM=2) is a conventional one 1410 and the TDD UL-DL configuration 1 isadapted to TDD UL-DL configuration 2 (bundling window size of M=4) 1420.Then, TTI #5 1430 for a conventional UE and TTI #4 1440 for UE 114supporting adaptive TDD UL-DL configuration have a same index inrespective bundling windows. If all other parameters in respective PUCCHresource determination functions are same, a conventional UE receivingPDSCH in TTI #5 and UE 114 supporting adaptive TDD UL-DL configurationreceiving PDSCH in TTI #4 will use a same PUCCH resource in TTI #2 1450for respective HARQ-ACK signaling, thereby leading to colliding PUCCHresources and unreliable receptions of HARQ-ACK signals.

Embodiments of this disclosure provide mechanisms for supporting UCItransmissions, and particularly HARQ-ACK transmissions, from UE 114configured for operation with an adaptive TDD UL-DL configuration.Embodiments of this disclosure provide a mechanism for avoiding resourcecollisions between a transmission of HARQ-ACK information from LTE 114configured to operate with an adaptive TDD UL-DL configuration and atransmission of HARQ-ACK information from UE 114 operating with anon-adapted TDD UL-DL configuration signaled by a system informationblock when both UE transmit HARQ-ACK information using PUCCH Format 1bwith HARQ-ACK multiplexing. Embodiments of this disclosure also providemechanisms for UE 114 to determine TTIs that are available for UCImultiplexing in a PUSCH depending on a UCI type and for accordinglyinterpreting fields of a DCI format scheduling a PUSCH transmission fromUE 114 in a TTL Moreover, embodiments of this disclosure provide amechanism to extend a size for a UCI payload that can be supported usingPUCCH Format 3. Furthermore, embodiments of this disclosure providemechanisms for UE 114 and eNB 102 to operate when UE 114 cannot detect aPDCCH conveying a DCI format adapting a TDD UL-DL configuration and eNB102 is aware of such event. Additionally, embodiments of this disclosureprovide mechanisms for UE 114 to inform eNB 102 of an actual of misseddetection for a PDCCH conveying a DCI format indicating an adapted TDDUL-DL configuration to a group of UEs. Finally, embodiments of thisdisclosure provide mechanisms for eNB 102 to use and for UE 114configured for operation with an adapted TDD UL-DL configuration tointerpret a field in a DCI format scheduling a PUSCH transmission aseither an UL DAI field or as an UL index field when TDD UL-DLconfiguration 0 is the conventional one and assumed for operation by UE114 when it misses a PDCCH conveying a DCI format informing of anadapted TDD UL-DL configuration.

Resources for PUCCH Format 1a/1b with HARQ-ACK Multiplexing for a UEConfigured for Operation with Adaptive TDD UL-DL Configuration

In certain embodiments, recognizing that only UL TTIs in a conventionalTDD UL-DL configuration can be flexible TTIs, it becomes apparent thatany adaptation of a conventional TDD UL-DL configuration can only havemore DL TTIs (and less UL TTIs). Therefore, a bundling window sizeM_(adapt) corresponding to DL TTIs for which HARQ-ACK is reported for anadapted TDD UL-DL configuration is larger than or equal to a bundlingwindow size M_(SI) corresponding to a conventional TDD UL-DLconfiguration, that is M_(adapt)≥M_(SI). Then, PUCCH resource collisionsfor a HARQ-ACK signal transmission from a conventional UE operating witha conventional TDD UL-DL configuration and a HARQ-ACK signaltransmission from UE 114 operating with an adapted TDD UL-DLconfiguration can occur in a same UL TTI as it was previously describedbased on Equation 1.

In a first approach, aforementioned PUCCH resource collisions (in a sameUL TTI) can be avoided by re-indexing DL TTIs that are in a bundlingwindow of size M_(adapt) but are not in a bundling window of size M_(S1)(needed only if M_(adapt)>M_(SI)−transmissions of respective HARQ-ACKsignals are assumed to be in a same UL TTI). The DL TTIs in a bundlingwindow of size M_(adapt) are a super-set of the DL TTIs in a bundlingwindow of size M_(SI). This re-indexing is possible because UE 114,which supports adaptation of a TDD UL-DL configuration, knows both aconventional TDD UL-DL configuration and the number of TTIs for whichHARQ-ACK needs to be reported when operating with an adapted TDD UL-DLconfiguration. Therefore, UE 114 knows the DL TTIs in a bundling windowof size M_(adapt) that are not included in DL TTIs in a bundling windowof size M_(SI).

An indexing of DL TTIs for determination of respective PUCCH resourcesfor HARQ-ACK signal transmissions is such that DL TTIs determined from aconventional TDD UL-DL configuration and additional DL TTIscorresponding to operation with an adapted TDD UL-DL configuration, thatare not included in the conventional TDD UL-DL configuration, areindexed in their original order after DL TTIs determined from theconventional TDD UL-DL configuration. Denoting by L_(adapt)={l₀, l₁, . .. l_(M) _(adapt) ⁻¹} a set of indexes of TTIs in a frame belonging to abundling window of size M_(adapt) and by K_(SI)={k₀, k₁, . . . K_(M)_(SI) ⁻¹} the indexes of TTIs in a frame belonging to a bundling windowof size M_(SI), with K_(SI) being a subset of L_(adapt), the setL_(adapt) is divided into two subsets L_(adapt) ^(SI) and L_(adapt)^(NSI) having no common elements where L_(adapt) ^(SI) is identical toK_(SI) and L_(adapt) ^(NSI) contains all indexes of TTIs in L_(adapt)that are not in K_(SI). Then, two bundling windows can be formed, wherethe first bundling window has size M_(SI) and the second bundling windowhas size M_(NSI)=M_(adapt)−M_(SI) both having HARQ-ACK signaltransmissions in a same UL TTI, with a first one including all TTIs insubset L_(adapt) ^(SI) and the second including all TTIs in subsetL_(adapt) ^(NSI). PUCCH resources are first allocated for HARQ-ACKsignal transmissions associated with TTIs in the first bundling windowand are subsequently allocated or HARQ-ACK signal transmissionsassociated with TTIs in the second bundling window. Therefore, in caseof PDCCH, Equation 1a is modified as in Equation 2a1n _(PUCCH)=(M _(SI) −m−1)·N _(c) +m·N _(c+1) +n _(CCE,n−k) _(m) +N_(PUCCH) ⁽¹⁾  (2a1)for TTIs with indexes in L_(adapt) ^(SI)=K_(SI) and as in Equation 2a2

$\begin{matrix}{n_{PUCCH} = {{\left( {M_{NSI} - m - 1} \right) \cdot N_{c}} + {m \cdot N_{c + 1}} + n_{{CCE},{n - k_{m}}} + N_{PUCCH}^{(1)} + {\sum\limits_{l = 0}^{M_{SI} - 1}\; N_{{CCE},l}}}} & \left( {2{a2}} \right)\end{matrix}$for TTIs with indexes in L_(adapt) ^(NSI) where N_(CCE,l) is a totalnumber of CCEs in TTI l of L_(adapt) ^(SI). Therefore, for the TDD UL-DLconfiguration UE 114 is configured by eNB 102 for HARQ-ACK signaltransmission, although the determination of M_(adapt) and of UL TTIs forHARQ-ACK signal transmission is according to TABLE 3, the ordering ofthe HARQ-ACK information bits transmitted in a same UL TTI is first forthe DL or special TTIs that are in M_(SI) and then for DL TTIs that arein M_(NSI).

In case of EPDCCH, a PUCCH resource n_(PUCCH) for a HARQ-ACK signaltransmission, in response to a detection of a respective PDCCH in a TTIwith index j in a frame and with index m in a bundling window, can bedetermined as in Equation 1 if j is an element of L_(adapt) ^(SI) (m isin first bundling window). If j is an element of L_(adapt) ^(NSI) (m isin second bundling window), it adapt can be determined as in Equation 2where the notation is same as in Equation 1.

$\begin{matrix}{n_{PUCCH} = {n_{{ECCE},{n - k_{m}}} + {\sum\limits_{j = 0}^{m - 1}\; N_{{ECCE},{n - k_{j}}}} + {\sum\limits_{l = 0}^{M_{SI} - 1}\; N_{{ECCE},{n - k_{l}}}} + {f({HRO})} + N_{PUCCH}^{({e\; 1})}}} & (2)\end{matrix}$

FIG. 15 illustrates an example indexing of DL TTIs in an adapted TDDUL-DL configuration, relative to a conventional TDD UL-DL configuration,for determining PUCCH resources for respective HARQ-ACK signaltransmissions according to this disclosure. The embodiment of theindexing shown in FIG. 15 is for illustration only. Other embodimentscould be used without departing from the scope of the presentdisclosure.

As shown in FIG. 15, if TDD UL-DL configuration 1 (bundling window sizeof M_(SI)=2) is a conventional one 1510 and the TDD UL-DL configuration1 is adapted to TDD UL-DL configuration 2 (bundling window size ofM_(adapt)=4) 1520 and HARQ-ACK transmission timing is based on TDD UL-DLconfiguration 2, then DL TTI #5 1530 and DL TTI #6 1540 are indexedfirst for determining PUCCH resources for respective HARQ-ACKtransmissions in UL TTI #2 1550. In general, DL TTIs in a conventionalTDD UL-DL configuration are indexed first using DL association indexingin TABLE 3. DL TTI #4 1560 and DL TTI #8 1570 are then sequentiallyindexed after DL TTI #5 and DL TTI #6. Therefore, for PUCCH resourcedetermination in UL TTI #2, a DL TTI indexing for the adapted TDD UL-DLconfiguration 2 is {DL TTI #5, DL TTI #6, DL TTI #4, DL TTI #8} 1580instead of a conventional indexing of {DL TTI #4, DL TTI #5, DL TTI #8,DL TTI #6} indicated in TABLE 3 (for TDD UL-DL configuration 2).Therefore, UE 114 configured to operate with an adapted TDD UL-DLconfiguration also operates with a modified DL association indexingwhere HARQ-ACK information for the flexible SFs is placed sequentiallyafter the HARQ-ACK information for DL fixed SFs according to a TDD UL-DLconfiguration used for UL HARQ-ACK transmissions by UEs configured tooperate with an adapted TDD UL-DL configuration.

In a second approach, the aforementioned PUCCH resource collisions canbe avoided by using a different N_(PUCCH) value for PUCCH resourcesassociated with DL TTIs included in an adapted TDD UL-DL configurationbut not included in a conventional TDD UL-DL configuration. This isparticularly applicable in case of PDCCH as in case of EPDCCH the AROfield can be used as a PUCCH resource offset.

With the second approach, a conventional method for PUCCH resourcedetermination as described by Equation 1 or by Equation 1 a is used but,similar to the first approach, a bundling window of size M_(adapt) foran adapted TDD UL-DL configuration is split into two bundling windows(both with HARQ-ACK signal transmission in a same first UL TTI). A firstbundling window of size M_(SI) contains TTIs with respective HARQ-ACKsignal transmissions in the same first UL TTI that are included in theconventional TDD UL-DL configuration. A second bundling window of sizeM_(NSI)=M_(adapt)−M_(SI) contains TTIs with respective HARQ-ACK signaltransmissions in a same first UL TTI that are not included in theconventional TDD UL-DL configuration. Additionally, UE 114 determines aPUCCH resource for a HARQ-ACK signal transmission in response to a PDSCHreception (or SPS release) using a first configured PUCCH resourceoffset N_(PUCCH,1) if a respective TTI is in the first bundling windowand using a second configured PUCCH resource offset N_(PUCCH) ⁽²⁾ if arespective TTI is in the second bundling window. Therefore, Equation 2a2for TTIs in the second bundling window is modified asn_(PUCCH)=(M_(NSI)−m−1)·N_(c)+m·N_(c+1)+n_(CCE,n−k) _(m) +N_(PUCCH) ⁽²⁾.Both the first and second PUCCH resource offsets, N_(PUCCH) ⁽¹⁾ andN_(PUCCH) ⁽²⁾, can be informed to UE 114 by eNB 102 through SIBsignaling or through higher layer signaling. For example, N_(PUCCH) ⁽¹⁾can be informed as described in REF3 and REF4 and N_(PUCCH) ⁽²⁾ can beconfigured to UE 114 by higher layer signaling. Alternatively, onlyN_(PUCCH) ⁽¹⁾ is informed to UE 114 and N_(PUCCH) ⁽²⁾ is implicitlydetermined from N_(PUCCH) ⁽¹⁾. Alternatively, N_(PUCCH) ⁽²⁾=N_(PUCCH)⁽²⁾+offset where offset is informed to UE 114 by eNB 102 using higherlayer signaling. Therefore, a PUCCH resource corresponding to a TTI inthe first bundling window or to a TTI in the second bundling window canbe determined as in Equation 1 (in case of EPDCCH) or Equation 1a (incase of PDCCH) wherein N_(PUCCH) ⁽¹⁾ is used for the first bundlingwindow and N_(PUCCH) ⁽²⁾ is used for the second bundling window.

In case of EPDCCH, eNB 102 can use the same values of N_(PUCCH) ⁽¹⁾ andN_(PUCCH) ⁽²⁾ or even not explicitly configure N_(PUCCH) ⁽²⁾ in whichcase N_(PUCCH) ⁽¹⁾ is always used. Then, as the first min (M_(SI),M_(NSI)) TTIs use a same set of PUCCH resources, collisions can beavoided by eNB 102 choosing an appropriate ARO value. In that casedifferent ARO mapping functions can be used for TTIs in the firstbundling window, f₁(ARO), and for TTIs in the second bundling window,f₂(ARO). Within a same bundling window, it is possible for a UE todetect a PDCCH in a first TTI and an EPDCCH in a second TTI.

FIG. 16 illustrates an example determination of a PUCCH resource forHARQ-ACK signal transmission using a PUCCH resource offset depending ona DL TTI index of a respective PDSCH reception in an adapted TDD UL-DLconfiguration according to this disclosure. The embodiment shown in FIG.16 is for illustration only. Other embodiments could be used withoutdeparting from the scope of the present disclosure.

As shown in FIG. 16, TDD UL-DL configuration 1 (bundling window size ofM_(SI)=2) is a conventional one and it is adapted to TDD UL-DLconfiguration 2 (bundling window size of M_(adapt)=4) 1610 and HARQ-ACKtransmission timing is based on TDD UL-DL configuration 2. For DL TTI #51620 and DL TTI #6 1630 (included in TDD UL-DL configuration 1), arespective PUCCH resource in UL TTI #2 1640 for a HARQ-ACK signaltransmission from UE 114 in response to a respective PDSCH reception (orSPS release) is determined using a first PUCCH resource offset N_(PUCCH)⁽¹⁾ 1650. For DL TTI #4 1660 and DL TTI #8 1670 (not included in PUCCHTDD UL-DL configuration 1), a respective PUCCH resource in UL TTI #21640 for a HARQ-ACK signal transmission from UE 114 in response to arespective PDSCH reception (or SPS release) is determined using a secondPUCCH resource offset N_(PUCCH) ⁽²⁾ 1680 which can be either explicitlysignaled to UE 114 or can be implicitly determined by UE 114 fromN_(PUCCH) ⁽¹⁾. Therefore, UE 114, configured for operation with anadapted TDD UL-DL configuration, can use two offsets for determiningresources to transmit HARQ-ACK information in an UL TTI using PUCCHFormat 1b with HARQ-ACK multiplexing. For determination of resourcescorresponding to TTIs that are the same as TTIs for which a UE operatingwith a conventional TDD UL-DL configuration transmits HARQ-ACKinformation in the UL TTI, a first offset is used. For determination ofresources corresponding to TTIs that are different than TTIs for which aUE operating with a conventional TDD UL-DL configuration transmitsHARQ-ACK information in the UL TTI, a second offset is used.

In a third approach, the aforementioned PUCCH resource collisions can beavoided by using a different PUCCH resource determination method for DLTTIs that are not included in a conventional TDD UL-DL configuration.

Similar to the first approach or the second approach, a bundling windowof size M_(adapt) corresponding to transmission of HARQ-ACK informationfrom UE 114 configured with an adapted TDD UL-DL configuration is splitinto two bundling windows (both with HARQ-ACK signal transmission in asame first UL TTI). A first bundling window of size M_(SI) contains TTIswith respective HARQ-ACK signal transmissions in a same first UL TTIthat are included in a conventional TDD UL-DL configuration. A secondbundling window of size M_(NSI)=M_(adapt)−M_(SI) contains TTIs withrespective HARQ-ACK signal transmissions in the same first UL TTI thatare not included in the conventional TDD UL-DL configuration. Aconventional method for PUCCH resource determination as described byEquation 1 (in case of EPDCCH) or Equation 1a (in case of PDCCH) is usedfor TTIs in the first bundling window.

For TTIs in the second bundling window, a PUCCH resource can beexplicitly indicated from a set of PUCCH resources that were previouslyconfigured to UE 114 by higher layer signaling (at least for DL TTIsoccurring earlier than a first DL TTI in a conventional TDD UL-DLconfiguration). Either same or different PUCCH resources can beconfigured by higher layer signaling for different DL TTIs. Theindication of a PUCCH resource can be through an ARO field in a DCIformat scheduling a respective PDSCH (or SPS release). For example, foran ARO field including 2 bits, one from four configured PUCCH resourcescan be indicated. Typically, as a number of DL TTIs included in thesecond bundling window is less than four, a same set of respective PUCCHresources can be used for all such DL TTIs if an ARO field of 2 bits isused to indicate 4 PUCCH resources. Unlike a determination of PUCCHresource corresponding to a TTI in the first bundling window for whichARO acts as an offset to an implicitly determined resource by UE 114(Equation 1), for a determination of PUCCH resource corresponding to aTTI in the second bundling window the ARO can instead directly index aPUCCH resource as n_(PUCCH)=g(HRO) where g(HRO) is an index to a PUCCHresource from one of at most four PUCCH resources configured to UE 114by eNB 102 through higher layer signaling in accordance to the thirdapproach. In case transmitter diversity is supported for HARQ-ACK signaltransmissions, g(HRO) is an index to a pair of PUCCH resources.

FIG. 17 illustrates an example implicit or explicit determination of aPUCCH resource for HARQ-ACK signaling depending on whether or not arespective DL TTI index is included in a conventional TDD UL-DLconfiguration, respectively, according to this disclosure. As shown inFIG. 17, it is assumed that TDD UL-DL configuration 1 is theconventional one indicated to conventional UEs and it is adapted to TDDUL-DL configuration 2 1710 and HARQ-ACK transmission timing is based onTDD UL-DL configuration 2. For DL TTI #5 1720 and DL TTI #6 1730(included in TDD UL-DL configuration 1), a respective PUCCH resource inUL TTI #2 1760 for a HARQ-ACK signal transmission from UE 114 inresponse to a respective PDSCH reception (or SPS release) is determinedusing a same method as for conventional UEs (method 1) 1722 and 1732,for example as in Equation 1. For DL TTI #4 1740 and DL TTI #8 1750 (notincluded in TDD UL-DL configuration 1), a respective PUCCH resource inUL TTI #2 1760 for a HARQ-ACK signal transmission from UE 114 inresponse to a respective PDSCH reception (or SPS release) is determinedusing a different method (method 2) 1742 and 1752. This different methodcan be explicit indication of a PUCCH resource, from a set of PUCCHresources configured to UE 114 by higher layer signaling, using the AROfield in a DCI format scheduling the PDSCH (or a SPS release) in arespective DL TTI.

TTI-Dependent UCI Multiplexing in a PUSCH

In certain embodiments, a first method for improving a detectionreliability of UCI multiplexed in a PUSCH is to link this multiplexingwith an UL PC process used for the PUSCH transmission. If the UL PCprocess is the one used for PUSCH transmissions in a first set of TTIs,such as UL fixed TTIs (will be referred to as first UL PC process), UE114 multiplexes UCI in the PUSCH. If the UL PC process is same as theone used for PUSCH transmissions in a second set of TTIs, such as ULflexible TTIs (will be referred to as second UL PC process), UE 114 doesnot multiplex UCI in the PUSCH. UE 114 can determine the UL PC processto apply for a PUSCH transmission either explicitly from a respectivefield included in a DCI format scheduling a PUSCH transmission or byconfiguration for a respective TTI in a frame or implicitly from a valueof a field included in a DCI format scheduling a PUSCH transmission andalso providing a different functionality (for example, a fieldindicating a CS and possibly an OCC for a DMRS transmission in a PUSCHwhere odd values can be also associated with a first UL PC process andeven values can be associated with a second UL PC process). UCI caninclude HARQ-ACK or P-CSI or their combination.

FIG. 18 illustrates an example determination by UE 114 whether tomultiplex UCI in a PUSCH depending on an associated UL PC processaccording to this disclosure. While the flow chart depicts a series ofsequential steps, unless explicitly stated, no inference should be drawnfrom that sequence regarding specific order of performance, performanceof steps or portions thereof serially rather than concurrently or in anoverlapping manner, or performance of the steps depicted exclusivelywithout the occurrence of intervening or intermediate steps. The processdepicted in the example depicted is implemented by a transmitter chainin, for example, a mobile station.

As shown in FIG. 18, UE 114 detects a PDCCH conveying a DCI formatscheduling a PUSCH in an UL TTI and determines a respective UL PC inoperation 1810. UE 114 is also assumed to have either HARQ-ACK or P-CSIto multiplex in the PUSCH. UE 114 examines whether the UL PC process isa first process or a second process in operation 1820. If the UL PCprocess for determining the PUSCH transmission power is the firstprocess, UE 114 multiplexes HARQ-ACK or P-CSI in the PUSCH in operation1830; otherwise, if the UL PC process for determining the PUSCHtransmission power is the second process, UE 114 does not multiplexHARQ-ACK or P-CSI in the PUSCH in operation 1840.

In a second method, for HARQ-ACK or P-CSI multiplexing in a PUSCH, thismultiplexing is entirely prohibited, regardless of the UL PC processused for the PUSCH transmission, unless the PUSCH is transmitted in asame TTI as a PUCCH UE 114 would use to transmit the HARQ-ACK or P-CSIwhen UE 114 does not have any PUSCH transmission. If UE 114 does nottransmit a UCI in the PUSCH, subsequent actions can depend on the UCItype. For HARQ-ACK transmission, UE 114 can proceed in a same manner aswhen UE 114 does not have a PUSCH transmission and transmit the HARQ-ACKin a PUCCH.

FIG. 19 illustrates an example determination by UE 114 whether tomultiplex UCI in a PUSCH depending on a respective TTI according to thisdisclosure. While the flow chart depicts a series of sequential steps,unless explicitly stated, no inference should be drawn from thatsequence regarding specific order of performance, performance of stepsor portions thereof serially rather than concurrently or in anoverlapping manner, or performance of the steps depicted exclusivelywithout the occurrence of intervening or intermediate steps. The processdepicted in the example depicted is implemented by a transmitter chainin, for example, a mobile station.

As shown in FIG. 19, UE 114 detects a PDCCH conveying a DCI formatscheduling a PUSCH in an UL TTI in operation 1910. UE 114 subsequentlydetermines whether the UL TTI is an UL TTI where UE 114 can transmitHARQ-ACK or P-CSI in a PUCCH in operation 1920. If the UL TTI supportsHARQ-ACK or P-CSI transmission from UE 114 in a PUCCH, UE 114multiplexes HARQ-ACK or P-CSI in the PUSCH in operation 1930; otherwise,if the UL TTI does not support HARQ-ACK or P-CSI transmission from UE114 in a PUCCH, UE 114 does not multiplex HARQ-ACK or P-CSI in the PUSCHin operation 1940. For example, a TTI supporting HARQ-ACK signaltransmission in a PUCCH can be an UL fixed TTI and a TTI not supportingHARQ-ACK signal transmission in a PUCCH can be an UL flexible TTI.

An UL DAI field included in a DCI format scheduling a PUSCH andindicating a number of PDSCHs for which UE 114 should multiplex HARQ-ACKin the PUSCH is not useful when HARQ-ACK is not multiplexed in thePUSCH. Utilization of the 2-bit UL DAI field in that case can be byeither always setting the 2-bit UL DAI field to zero, so that UE 114 cancheck its value when determining whether the validity of the fields in adetected DCI format, or by using the 2-bit UL DAI field as an additionalTPC field in order to increase a number of TPC bits used by the CLPCcomponent of the second UL PC process and enhance an accuracy of thesecond UL PC process, or for any other functionality related to PUSCHtransmissions.

FIG. 20 illustrates an example use of an UL DAI field included in a DCIformat scheduling a PUSCH transmission in a TTI depending on whether ornot UE 114 multiplexes HARQ-ACK in the PUSCH in the TTI according tothis disclosure. While the flow chart depicts a series of sequentialsteps, unless explicitly stated, no inference should be drawn from thatsequence regarding specific order of performance, performance of stepsor portions thereof serially rather than concurrently or in anoverlapping manner, or performance of the steps depicted exclusivelywithout the occurrence of intervening or intermediate steps. The processdepicted in the example depicted is implemented by a transmitter chainin, for example, a mobile station.

As shown in FIG. 20, UE 114 detects a PDCCH conveying a DCI formatscheduling a PUSCH in an UL TTI and including an UL DAI field inoperation 2010. UE 114 subsequently determines whether the UL TTI is anUL TTI where UE 114 can multiplex HARQ-ACK in the PUSCH in operation2020, for example using one of the previously described methods. If theUL TTI supports HARQ-ACK signal transmission from UE 114 in the PUSCH,UE 114 determines an HARQ-ACK payload to multiplex in the PUSCHaccording to a value of the UL DAI field in operation 2030; otherwise,if the UL TTI does not support HARQ-ACK signal transmission from UE 114in the PUSCH, UE 114 uses the UL DAI field to complement a TPC fieldincluded in the DCI format in order to increase a number of TPC bits forclosed-loop power control of the PUSCH transmission and enhance arespective reception reliability in operation 2040. Alternatively, theUL DAI field value can be set to a predetermined value such as ‘00’ thatUE 114 can confirm before further considering the DCI format as valid.Alternatively, the UL DAI field value can be used for any otherfunctionality related to PUSCH transmissions.

In case HARQ-ACK is multiplexed in a PUSCH only when the PUSCH istransmitted in a same TTI as a PUCCH UE 114 would use for transmittingHARQ-ACK information when it does not transmit a PUSCH, the effectivebundling window M_(adapt) is different than a conventional one M_(SI) asit was previously described. A mapping of an UL DAI field should alsoreflect an effective bundling window size M_(adapt).

Unlike potential resource collisions for transmission of HARQ-ACKinformation using PUCCH format 1b with channel selection between UE 114,configured to operate with an adapted TDD UL-DL configuration, and UE115, operating with a conventional TDD UL-DL configuration as it waspreviously described, such collisions do not occur when HARQ-ACKinformation is transmitted in a PUSCH. Therefore, for UE 114 configuredto operate with an adaptive TDD UL-DL configuration, the ordering ofHARQ-ACK information does not need to be modified by placing firstHARQ-ACK information bits corresponding to a first set of TTIs andplacing second HARQ-ACK information bits corresponding to a second setof TTIs. Instead, the ordering of HARQ-ACK information bits forrespective TTIs is according to the timing described in TABLE 3 for aTDD UL-DL configuration that is configured to UE 114 for transmission ofHARQ-ACK information.

FIG. 21 illustrates an example effective bundling window size ifHARQ-ACK is only multiplexed in a PUSCH of predetermined UL TTIsaccording to this disclosure. The embodiment of the PUSCH shown in FIG.21 is for illustration only. Other embodiments could be used withoutdeparting from the scope of the disclosure.

As shown in FIG. 21, TDD UL-DL configuration 1 is used (bundling windowsize of M_(SI)=2) for illustration purposes only. In a conventional useof an UL DAI field, when eNB 102 schedules a PDSCH transmission to UE114 in SF #4 2110, eNB 102 expects a respective HARQ-ACK transmissionfrom UE 114 in SF #8 2120. Therefore, when eNB 102 schedules PUSCHtransmission to UE 114 in SF #8, an UL DAI field with a value of 1 in arespective DCI format indicates that UE 114 shall multiplex HARQ-ACK fora PDSCH transmission (or SPS release) in SF #4. Similar, when eNB 102schedules a PDSCH transmission to UE 114 in either or both of SF #5 2130and SF #6 2132, eNB 102 expects a respective HARQ-ACK transmission fromUE 114 in SF #2 2140 and when eNB 102 schedules PUSCH transmission to UE114 in SF #2, an UL DAI field with a value of 1 or 2, respectively, in arespective DCI format indicates the number of PDSCHs (or SPS release)for which UE 114 shall multiplex HARQ-ACK in the PUSCH. Assuming that SF#8 2162 is an UL flexible TTI, UE 114 does not support HARQ-ACKmultiplexing in a PUSCH transmission in SF #8. Then, eNB 102 expects UE114 to multiplex HARQ-ACK for a PDSCH scheduled in SF #4 in the firstTTI after SF #8 where UE 114 can transmit HARQ-ACK in a PUCCH. In theexemplary case of TDD UL-DL configuration 1, that UL TTI is SF #2.Therefore, when eNB 102 schedules a PDSCH transmission to UE 114 ineither of SF #4 2150, SF #5 2152 and SF #6 2154, eNB 102 expects arespective HARQ-ACK transmission from UE 114 in SF #2 2160 and when itschedules PUSCH transmission to UE 114 in SF #2, an UL DAI field with avalue of 1 or 2 or 3, depending on whether a number of PDSCH (or SPSrelease) scheduled in SF #4, SF #5, and SF #6 is respectively, 1 or 2 or3, in a respective DCI fonnat indicates a number of PDSCHs for which UE114 shall multiplex HARQ-ACK in the PUSCH. Therefore, for UE 114configured to operate with an adapted TDD UL-DL configuration, a mappingfor values of an UL DAI field is according to a configured TDD UL-DLconfiguration UE 114 considers in determining UL TTIs available fortransmission of HARQ-ACK.

For A-CSI, if a transmission does not occur in a respective PUSCH, thetransmission cannot occur in a subsequent PUCCH as a respective A-CSIpayload cannot be supported by a PUCCH format used to transmit P-CSI andUE 114 may have another A-CSI to transmit in a next PUSCH transmission.Therefore, for A-CSI, two alternatives can exist.

A first alternative is to always transmit A-CSI in a PUSCH. As an A-CSIcodeword is assumed to also include a CRC, eNB 102 can determine if itincorrectly decodes an A-CSI codeword. If the PUSCH transmission usesthe second UL PC process, the A-CSI resources in the PUSCH can be largerthan respective ones for a same PUSCH transmission using the first UL PCprocess. Therefore, multiplexing of UCI in a PUSCH can be furtherconditioned on the UCI type with HARQ-ACK or P-CSI not multiplexed inthe PUSCH, under previously described conditions, while A-CSI is alwaysmultiplexed in a PUSCH when a respective A-CSI request field in a DCIformat scheduling the PUSCH transmission indicates that UE 114 shallmultiplex A-CSI in its PUSCH transmission.

FIG. 22 illustrates an example UE decision for multiplexing UCI in aPUSCH transmitted in a TTI according to a UCI type and the TTI typeaccording to this disclosure. While the flow chart depicts a series ofsequential steps, unless explicitly stated, no inference should be drawnfrom that sequence regarding specific order of performance, performanceof steps or portions thereof serially rather than concurrently or in anoverlapping manner, or performance of the steps depicted exclusivelywithout the occurrence of intervening or intermediate steps. The processdepicted in the example depicted is implemented by a transmitter chainin, for example, a mobile station.

As shown in FIG. 22, UE 114 detects a PDCCH conveying a DCI formatscheduling a PUSCH in an UL TTI an including an UL DAI field inoperation 2210. UE 114 subsequently determines whether the UL TTI is anUL fixed TTI, or an UL TTI using a first UL PC process, where PUCCH canbe transmitted as it was previously described in operation 2220. If theUL TTI is a UL fixed TTI (or an UL TTI where UE 114 can transmitHARQ-ACK in a PUCCH, or an UL TTI using a first UL PC process), UE 114multiplexes HARQ-ACK and A-CSI in the PUSCH in operation 2230;otherwise, if the UL TTI is not an UL fixed TTI (or an UL TTI where UE114 cannot transmit HARQ-ACK in a PUCCH, or an UL TTI using a second ULPC process), UE 114 multiplexes only A-CSI in the PUSCH in operation2240.

A second alternative is for UE 114 to always drop A-CSI transmission ina PUSCH that uses a second UL PC process or if the PUSCH transmission isin an UL TTI where PUCCH transmissions are not supported for UE 114. Inthat case, the 1-bit A-CSI request field that is included in a DCIformat scheduling the PUSCH is not used. Utilization of the 1-bit A-CSIrequest field in that case can be by either always setting the 1-bitA-CSI request field to zero, so that UE 114 can check its value whendetermining whether the validity of the fields in a detected DCI format,or by using the 1-bit A-CSI request field as a TPC bit in order toincrease a number of TPC bits used by the CLPC component of the secondUL PC process and enhance an accuracy of the second UL PC process, or byusing it for any other functionality related to PUSCH transmissions. UE114 behavior in this case is similar as the one described for the UL DAIfield in FIG. 20.

Finally, although the previous descriptions of the various aspects ofthe first embodiment of the disclosure considered a PUSCH scheduled by aDCI format in a detected PDCCH, a same UE behavior (when applicable) canexist when a PUSCH retransmission is triggered by a PHICH detection. SPSPUSCH is assumed to be in UL fixed TTIs and UE 114 can followconventional methods for multiplexing UCI in a SPS PUSCH.

UCI Multiplexing in a PUCCH for a UE Configured for Operation withAdaptive TDD UL-DL Configuration

Certain embodiments consider multiplexing of two P-CSI reports in a samePUCCH. This is motivated from a need to support reporting from UE 114 ofa first P-CSI corresponding a DL fixed TTI and of at least a secondP-CSI corresponding to a DL flexible TTI and from a limitation of ULTTIs where a PUCCH can exist for P-CSI reporting (for example, only inUL fixed TTIs). It is assumed that UE 114 cannot simultaneously transmitUCI in two different PUCCHs.

UE 114 can be configured by eNB 102 a first set of DL or special TTIsfor determining a first CSI and a second set of DL or special TTIs fordetermining a second CSI where the configuration can be by using abit-map of 9 bits to include a maximum of TTIs in a TDD UL-DLconfiguration that can be DL or special TTIs (TTI #2 is always an ULTTI). For example a bit-map can be {0 0 1 1 0 0 1 1 0} where a value of‘0’ indicates a TTI in the first set and a value of ‘1’ indicates a TTIin the second set. Alternatively, a bit-map can be defined in a samemanner relative to the DL or special TTIs of a TDD UL-DL configurationeNB 102 configures to UE 114 for determining one or more UL TTIs fortransmission of HARQ-ACK information.

As a P-CSI difference between a DL fixed TTI and a DL flexible TTI is ina respective interference experienced for DL receptions by UE 114, asingle PMI suffices for both P-CSI reports and either the P-CSI for a DLflexible TTI or the P-CSI for a DL fixed TTI does not need to include aPMI. Therefore, a P-CSI reporting mode (defining whether PMI ismultiplexed (see also REF 3)) can be configured separately for a firstset of TTIs, such as a set of DL fixed TTIs, and for a second set ofTTIs, such as a set of DL flexible TTIs. This is applicable regardlessof whether Time Division Multiplexing (TDM) is used for transmissions ofa first P-CSI and a second P-CSI so that they can occur in different ULTTIs or whether these two P-CSIs are multiplexed in a same PUCCH (and ina same UL TTI). Moreover, UE 114 can compute a PMI only in a first setof TTIs or in a second set of TTIs or combine a PMI computation using atleast a TTI from the first set of TTI and at least a TTI from the secondset of TTIs.

It is therefore beneficial to support multiplexing in a same PUCCH oftwo CQIs, corresponding to two different sets of TTIs that areconfigured to UE 114 by eNB 102, and of a single PMI corresponding toboth DL TTI sets, such as a set of DL fixed TTIs and a set of DLflexible TTIs. It is also possible, according to a configuration of aCSI reporting type to UE 114, for the P-CSI report to include only thetwo CQIs for the respective two sets of TTIs.

FIG. 23 illustrates an example multiplexing in a same PUCCH of a firstCQI corresponding to a first set of TTIs (such as a set of DL fixedTTIs), of a second CQI corresponding to a second set of TTIs (such as DLflexible TTIs), and of a single PMI corresponding to both sets of TTIsaccording to this disclosure. The embodiment of the TDD configuration2300 shown in FIG. 23 is for illustration only. Other embodiments couldbe used without departing from the scope of the disclosure.

As shown in FIG. 23, a TDD UL-DL configuration 1 is used forillustration purposes only. UE 114 computes a first P-CQI in a DL fixedTTI SF #5 2310 and computes a second P-CQI in a DL flexible TTI SF #42320 and a single PMI, in either or both DL fixed TTI SF #5 and DLflexible TTI SF #4, and reports the first P-CQI, the second P-CQI, andthe PMI in a PUCCH in UL TTI SF #2 2330.

As the second CQI is likely to be better (higher) than the first CQI,since DL transmissions in a DL flexible TTI can experience UL-dominantinterference (that is typically smaller than DL-dominant interferenceexperienced by DL transmissions in a DL fixed TTI), the second CQI canbe reported in a differential manner to the first CQI with most valuesindicating a higher CQI. For example, the second CQI can be representedby 2 binary elements, instead of 4 binary elements used to indicate thefirst CQI, and the 2 binary elements can be used to indicate one smallerand three larger indexes for the second CQI compared to the index of thefirst CQI. Therefore, a second CQI for a second set of subframes caninclude a second set of values where at least one value in the secondset of values is larger than the largest value in a first set of values,such as the set in TABLE 1, for a first CQI for a first set ofsubframes.

In a first example, for a differential reporting of a second CQIrelative a to a first CQI using two binary elements, a first value canindicate an index that is two values smaller (when applicable) than anindex of the first CQI and second, third, and fourth values can be same,two values larger, and four values larger than the index of the firstCQI, respectively. Then, referring to TABLE 1, for a first CQI valueindicating an index 4, the second CQI value can indicate a CQI index of2, 4, 6, or 8. In a second example, for the second CQI, a first valuecan indicate an index that is same as an index for the first CQI andsecond, third, and fourth values can be two values larger, four valueslarger, and six values larger (when applicable, if the largest possiblevalue is not reached), respectively, than the index of the first CQI.Then, referring to TABLE 1, for a first CQI value indicating an index 4,the second CQI value can indicate either a CQI index of 4, 6, 8, or 10.In case of reporting more than two P-CSIs, remaining P-CSIs can beprovided in a same manner as it was previously described for the secondP-CSI.

Moreover, UE 114 can be configured with a different PDSCH transmissionmode in a DL fixed TTI and in a DL flexible TTI including support ofdifferent modulation schemes. For example, in a first set of TTIs, suchas DL fixed TTIs, a PDSCH transmission can be configured to use a firsttransmission mode or a maximum modulation order of 64 QuadratureAmplitude Modulation (QAM) while in a second set of TTIs, such as DLflexible TTIs, UE 114 can be configured to use a second PDSCHtransmission mode or a maximum modulation order of 256QAM. Therefore, inthe first set of TTIs, TABLE 1 and TABLE 1A can be used, while in thesecond set of TTIs, eNB 102 can configure UE 114 to use either TABLE 1and TABLE 1A or a modified TABLE 1 and a modified TABLE 1A that includesupport for 256QAM modulation.

Instead of using a same PUCCH format for multiplexing both a P-CSI for afirst set of DL TTIs and a P-CSI for a second set of DL TTIs as thePUCCH format used to transmit a single P-CSI (also referred as PUCCHFormat 2, see also REF 1), the multiplexing of the two P-CSIs can be ina PUCCH format (PUCCH Format 3) with structure such as the one describedin FIG. 7. Additionally, multiplexing of HARQ-ACK and of previous 2P-CSIs can be supported by a same PUCCH format such as the one describedin FIG. 7.

FIG. 24 illustrates an example UE transmitter block diagram forHARQ-ACK, P-CSI for a first set of TTIs, and P-CSI for a second set ofTTIs according to this disclosure. The embodiment of the UE transmitter2400 shown in FIG. 24 is for illustration only. Other embodiments couldbe used without departing from the scope of the present disclosure. Incertain embodiments, the UE transmitter 2400 is located in the UE 114.

As shown in FIG. 24, assuming the structure in FIG. 7, UE 114transmitter encodes and modulates 2410 HARQ-ACK bits 2405 and P-CSI bits2408 and multiplies the encoded and modulated bits with an element of anOCC 2425 for a respective TTI symbol 2420. The P-CSI bits include a PMIand a CQI for a DL fixed TTI and a CQI for a DL flexible TTI. After DFTprecoding 2430, UE 114 transmitter selects REs 2440 of a PUCCH RB 2450,applies an IFFT 2460, inserts a CP 2470, applies filtering 2480, andtransmits the signal 2490.

FIG. 25 illustrates an example eNB receiver block diagram for HARQ-ACK,P-CSI for a first set of TTIs, and P-CSI for a second set of TTIsaccording to this disclosure. The embodiment of the eNB receiver 2500shown in FIG. 25 is for illustration only. Other embodiments could beused without departing from the scope of the disclosure. In certainembodiments, the eNB receiver 2500 is located in eNB 102.

As shown in FIG. 25, eNB 102 receiver filters 2520 a received signal2510, applies a FFT 2530, selects 2545 REs 2540 used by UE 114transmitter, applies an IDFT 2550, multiplies 2560 with an OCC element2565 for a respective symbol, sums outputs for symbols conveyingHARQ-ACK signals and P-CSI signals 2570, and demodulates and decodessummed HARQ-ACK signals and P-CSI signals 2580 to obtain transmittedHARQ-ACK bits 2585 and P-CSI bits 2588.

As an interference experienced by a PDSCH transmission to UE 114 dependson whether a respective DL TTI is a fixed one or a flexible one, withthe interference typically being smaller for the latter if a respectiveTTI in a dominant interfering cell in an UL one, a different PDSCHtransmission rank can apply between PDSCH transmissions in DL fixed TTIand in DL flexible TTI with the rank for the latter being same to orlarger than the rank for the former. Therefore, UE 114 can provide aseparate RI for a DL fixed TTI and for a DL flexible TTI. Similar to aP-CSI for a DL flexible TTI, a respective RI can be provided in adifferential manner. For example, only 1 bit can be used for an RIreport for a DL flexible TTI indicating whether a same rank or animmediately higher rank can apply for a PDSCH transmission in a DLflexible TTI. For example, if an RI report for a DL fixed TTI consistsof 2 bits indicating a PDSCH transmission rank of 1, 2, or 4 spatiallayers and a RI value indicates 1 spatial layer, a RI report for a DLflexible TTI can consist of 1 bit indicating a PDSCH transmission rankof either 1 spatial layer or 2 spatial layers. As a TDD UL-DLconfiguration can remain valid for only a limited number of TTIs, UE 114may need to report RI for a DL flexible TTI within a validity period ofa TDD UL-DL configuration. Given a limited number of UL TTIs where suchan RI report can be transmitted, it becomes beneficial to enablemultiplexing of RI and P-CSI reports in a same PUCCH. Therefore,embodiments of the present disclosure further consider UE 114 supportingadaptation of a TDD UL-DL configuration, an RI report for a DL fixed TTIand a RI report for a DL flexible TTI can be multiplexed in a same PUCCHand can also be multiplexed together with a P-CSI report for a DL fixedTTI or for a DL flexible TTI.

Extending Payload Support for PUCCH Format 3

In certain embodiments, UE 114 configured for operation with an adaptiveTDD UL-DL configuration can use a PUCCH Format 3 that can be configuredto be transmitted over one RB or over multiple RBs depending on a UCIpayload.

UE 114 can be configured to transmit a PUCCH Format 3 over 2 RBs, forexample at least when TDD UL-DL configuration 5 is configured to UE 114for determining TTIs for which UE 114 needs to provide HARQ-ACKinformation or at least when UE 114 transmits P-CSI together withHARQ-ACK. By using 2 RBs, instead of 1 RB, for a transmission of a PUCCHFormat 3, a respective resource overhead doubles but UCI payloads thatcan be supported with target reception reliability also practicallydouble. In general, varying a number of RBs used for a PUCCH Format 3transmission allows for scalability in a transmitted UCI payload forsimilar reception reliability, without dropping any UCI or applyingexcessive HARQ-ACK bundling, while maintaining a PUCCH Format 3structure and maintaining a single PUCCH transmission from UE 114 in anUL TTI.

FIG. 26 illustrates an example resource allocation for PUCCH Format 3depending on a maximum total payload according to this disclosure. Whilethe flow chart depicts a series of sequential steps, unless explicitlystated, no inference should be drawn from that sequence regardingspecific order of performance, performance of steps or portions thereofserially rather than concurrently or in an overlapping manner, orperformance of the steps depicted exclusively without the occurrence ofintervening or intermediate steps. The process depicted in the exampledepicted is implemented by a transmitter chain in, for example, a mobilestation.

As shown in FIG. 26, UE 114 determines a total UCI payload in operation2610 to transmit in a PUCCH. This determination can be semi-static byconfiguration as UE 114 is configured a P-CSI reporting mode and isconfigured a TDD UL-DL configuration for HARQ-ACK transmissions. The UCIincludes HARQ-ACK, P-CSI, or SR. For HARQ-ACK, UE 114 determines apayload from a configured PDSCH transmission mode (based on whether aPDSCH can convey one data TB or two data TBs), from a number of DL TTIsin a TDD UL-DL configuration assumed for HARQ-ACK transmission in caseof operation in a TDD system, or from a number of configured DL carriersin case UE 114 operates with DL CA. If a UCI payload O_(UCI) does notexceed a predetermined threshold in operation 2620, such as for example22 bits, a PUCCH Format 3 over one RB in operation 2630 can beconfigured to UE 114 by eNB 102 and UCI encoding can be by a first RMcode, such as a (32, O_(UCI)) RM code punctured to a (24, O_(UCI)). Ifthe UCI payload exceeds the threshold, a PUCCH Format 3 over two RBs inoperation 2640 can be configured to UE 114 by eNB 102 and UCI encodingcan be with a second RM code, such as a (64, O_(UCI)) RM code puncturedto a (48, O_(UCI)) RM code or a dual (24, O_(UCI)) RM code where each(24, O_(UCI)) RM code is applied over 1 RB. Alternatively, aconvolutional code instead of a RM code can be used when UE 114transmits UCI over two RBs. For example, when UE 114 transmits HARQ-ACKwithout P-CSI, a payload may not exceed the predetermined thresholdwhile when UE 114 transmits HARQ-ACK and P-CSI, a payload can exceed thepredetermined threshold. UE 114 can therefore have a first PUCCH Format3 resource configured for the first UCI payload case and a second PUCCHFormat 3 configured for the second UCI payload case.

If a dual (24, O_(UCI)) RM code (with QPSK modulation) is used over 2RBs, with each (24, O_(UCI)) RM code applied over 1 RB, it is possibleto multiplex in a same RB a transmission of a PUCCH Format 3 from afirst UE 114 transmitting in only 1 RB and a transmission of a PUCCHFormat 3 from a second UE 115 transmitting in 2 RBs. Moreover, when UE114 determines a PUCCH Format 3 transmission over 2 RBs (based on arespective determined UCI payload), UE 114 interprets an indication of arespective resource in a DL DCI format as being applicable over 2 RBs;otherwise, if UE 114 determines a PUCCH Format 3 transmission over 1 RB,UE 114 interprets an indication of a respective resource in a DL DCIformat as being applicable over 1 RB.

FIG. 27 illustrates an example PUCCH Format 3 transmission over 2 RBsaccording to this disclosure. The example of the PUCCH Format 3transmission shown in FIG. 27 is for illustration only. Otherembodiments could be used without departing from the scope of thedisclosure.

As shown in FIG. 27, in a first realization, UE 114 splits O_(UCI)information bits in a first RM code and in a second RM code in analternating manner, for example by placing even-indexed (starting from0) UCI bits to the first RM code and odd-indexed UCI bits to the secondRM code. ┌O_(UCI)/2┐ UCI bits are then placed in the first (24,┌O_(UCI)/2┐) RM code 2710 and └O_(UCI)/2┘ UCI bits are placed in thesecond (24, └O_(UCI)/2┘) RM code 2720 where ┌ ┐ is the ceiling functionrounding a number to its immediately higher integer and └ ┘ is the floorfunction rounding a number to its immediately lower integer. UE 114transmits, using QPSK modulation and a PUCCH Format 3 structure in eachRB of two RBs, 24 encoded UCI bits from a first RM code in a first RB2715 and 24 encoded UCI bits from a second RM code in a second RB 2725.In a second realization, encoded and modulated bits of a first (24,┌O_(UCI)/2┐) RM code 2730 and of a second (24,┌O_(UCI)/2┐) RM code 2740are placed in REs of 2 RBs in an alternating manner 2735, 2745. In athird realization, UE 114 encodes O_(UCI) bits using a single (48,O_(UCI)) RM code 2750 and transmits, using QPSK modulation and PUCCHFormat 3 structure, the encoded and modulated UCI bits over 2 RBs 2760.

Missed Detection of a PDCCH Conveying a DCI Format Adapting a TDD UL-DLConfiguration

In certain embodiments, UE 114 operating with an adapted TDD UL-DLconfiguration does not detect a PDCCH indicating a new adapted TDD UL-DLconfiguration and eNB 102 that transmitted the PDCCH is aware of thatevent. For example, eNB 102 can be aware that UE 114 is in a DRX mode ina TTI of the PDCCH transmission.

When UE 114 operating with an adapted TDD UL-DL configuration does notdetect a PDCCH indicating a new adapted TDD UL-DL configuration, UE 114then can operate with a conventional TDD UL-DL configuration, or with aknown to UE 114 TDD UL-DL configuration such as a previously configuredTDD UL-DL configuration (possibly separate for DL reception and for ULtransmissions), or attempt to detect PDCCH in every TTI (except TTI #2)and follow a respective DL or UL scheduling assignment (if any), untilUE 114 later detects another PDCCH indicating a new adapted TDD UL-DLconfiguration. However, in case UE 114 operates with a non-adapted TDDUL-DL configuration, UE 114 may not behave according to the non-adaptedTDD UL-DL configuration with respect to its HARQ-ACK transmissions asthere can be residual HARQ-ACK information corresponding to PDCCHdetections during a last adapted TDD UL-DL configuration that UE 114needs to transmit in a TTI occurring after a last TTI of the lastadapted TDD UL-DL configuration.

To address the above problem, certain embodiments of this disclosureconsider that a UE, such as UE 114, operating with an adapted TDD UL-DLconfiguration and does not detect a PDCCH indicating a new adapted TDDUL-DL configuration, continues to transmit HARQ-ACK information using asame reference TDD UL-DL configuration, such as for example TDD UL-DLconfiguration 5, as when UE 114 operates with an adapted TDD UL-DLconfiguration. Even through DL or UL scheduling purposes, UE 114operates with a conventional TDD UL-DL configuration after a last TTI ofa current adapted TDD UL-DL configuration. The use of the previousreference TDD UL-DL configuration can be always applicable or can berestricted only to the first UL TTI of a non-adapted TDD UL-DLconfiguration. Moreover, the eNB 102 receiver can use this knowledge toimprove detection reliability of a HARQ-ACK codeword by assuming that UE114 places a NACK/DTX value in the HARQ-ACK codeword at each locationcorresponding to a DL TTI that is an UL TTI in the conventional TDDUL-DL configuration. Additionally, to improve detection reliability of aHARQ-ACK codeword transmitted using a PUCCH Format 3, UE 114 canrearrange the order of DL TTIs as it was described in the firstembodiment of the disclosure by placing first HARQ-ACK informationcorresponding to DL fixed TTIs and placing second HARQ-ACK informationcorresponding to DL flexible TTIs (that are UL TTIs in the conventionalTDD UL-DL configuration) as the former can convey actual HARQ-ACKinformation while the latter can convey only NACK/DTX.

FIG. 28 illustrates an example DL or UL scheduling and HARQ-ACKtransmission for UE 114 operating with an adapted TDD UL-DLconfiguration followed by operation with a conventional TDD UL-DLconfiguration according to this disclosure. While the flow chart depictsa series of sequential steps, unless explicitly stated, no inferenceshould be drawn from that sequence regarding specific order ofperformance, performance of steps or portions thereof serially ratherthan concurrently or in an overlapping manner, or performance of thesteps depicted exclusively without the occurrence of intervening orintermediate steps. The process depicted in the example depicted isimplemented by a transmitter chain in, for example, a mobile station.

As shown in FIG. 28, while UE 114 operates with an adapted TDD UL-DLconfiguration, UE 114 monitors PDCCH in DL TTIs of the adapted TDD UL-DLconfiguration and transmits HARQ-ACK information following a referenceTDD UL-DL configuration in operation 2810. After a last TTI of anadapted TDD UL-DL configuration, as determined by UE 114 from a knownvalidity period of the adapted TDD UL-DL configuration, UE 114determines whether it has detected a PDCCH informing of a new adaptedTDD UL-DL configuration in operation 2820. If it has not, UE 114monitors PDCCH in DL TTIs of a conventional TDD UL-DL configuration orin every TTI other than TTI #2, but continues to transmit HARQ-ACKinformation following the reference TDD UL-DL configuration in operation2830. If it has, UE 114 monitors PDCCH in DL TTIs of the new adapted TDDUL-DL configuration and transmits HARQ-ACK information following thereference TDD UL-DL configuration in operation 2840.

The present embodiment can be modified in case UE 114 does not detect aPDCCH informing of an adapted TDD UL-DL configuration over one or morevalidity periods of an adapted TDD UL-DL configuration. A validityperiod can include a number of TTIs or a number of frames. When there isno residual HARQ-ACK information corresponding to an adapted TDD UL-DLconfiguration, UE 114 can transmit HARQ-ACK information according to thenon-adapted TDD UL-DL configuration. Therefore, UE 114 can determine aHARQ-ACK payload and an UL TTI for HARQ-ACK signal transmission, asdescribed in TABLE 3, according to the non-adapted TDD UL-DLconfiguration. UE 114 can also use a first PUCCH format to transmitHARQ-ACK information associated with an adapted TDD UL-DL configurationand use a second PUCCH format to transmit HARQ-ACK informationassociated with a non-adapted TDD UL-DL configuration, where the firstPUCCH format can be different than the second PUCCH format.

Finally, when UE 114 operates with a non-adapted TDD UL-DL configurationfollowed by an adapted TDD UL-DL configuration, HARQ-ACK transmission ina first UL TTI of the adapted TDD UL-DL configuration can be accordingto a same method as for the non-adapted TDD UL-DL configuration,including a determination of a HARQ-ACK payload and a use of a PUCCHformat for the HARQ-ACK transmission. For remaining TTIs during theadapted TDD UL-DL configuration, HARQ-ACK transmission can be accordingto a reference TDD UL-DL configuration, such as for example TDD UL-DLconfiguration 5. For example, when UE 114 transmits HARQ-ACK informationcorresponding to DL scheduling during an adapted TDD UL-DLconfiguration, UE 114 can determine a HARQ-ACK payload according to abundling window size for a respective TDD UL-DL configuration and use aPUCCH format 3 to transmit the HARQ-ACK information. Conversely, when UE114 transmits HARQ-ACK corresponding to DL scheduling during anon-adapted TDD UL-DL configuration, it can determine a HARQ-ACK payloadaccording to a bundling window size for the non-adapted TDD UL-DLconfiguration and use HARQ-ACK multiplexing with PUCCH format 1b totransmit the HARQ-ACK information.

HARQ-ACK Feedback from a UE Regarding a Detection of a PDCCH Conveying aDCI Format Informing of an Adapted TDD UL-DL Configuration

In certain embodiments, UE 114 transmits HARQ-ACK information to eNB 102regarding a detection of a PDCCH transmitted from eNB 102 and conveyinga DCI format informing of an adapted TDD UL-DL configuration.

As a PDCCH conveying information for an adapted TDD UL-DL configurationcan be detected by a group of UEs, UE 114 may not be able to determine aPUCCH resource (unique for UE 114) for a transmission of HARQ-ACKinformation informing eNB 102 whether UE 114 detected the PDCCH. In afirst alternative, the PDCCH is transmitted in one or more predeterminedTTIs and eNB 102 can explicitly configure using higher layer signaling,to each UE in the group of UEs, a PUCCH resource for HARQ-ACKtransmission in response to a detection (or absence of detection) of thePDCCH.

In a second alternative, UE 114 can include such HARQ-ACK informationtogether with subsequent HARQ-ACK information regarding PDCCH detectionsassociated with DL scheduling from eNB 102. For example, whentransmitting HARQ-ACK information using a PUCCH Format 3, as it waspreviously described, UE 114 can also include one HARQ-ACK informationbit informing eNB 102 whether UE 114 detected (ACK) or failed to detect(DTX) a PDCCH indicating an adaptation of a current TDD UL-DLconfiguration or, in general, a PDCCH conveying DCI to a group of UEs.UE 114 can transmit a HARQ-ACK information bit regarding a detection ofa PDCCH intended for a group of UEs in a predetermined location in acodeword conveyed by PUCCH Format 3, such as for example a firstlocation or a last location.

By providing eNB 102 with HARQ-ACK information for whether or not itdetected a PDCCH conveying information for an adapted TDD UL-DLconfiguration, UE 114 can improve its throughput in case UE 114 failedto detect the PDCCH, for example as eNB 102 can know to avoidtransmitting scheduling assignments to UE 114 in DL TTIs UE 114considers as UL TTIs or UE 114 can avoid power consumption associatedwith decoding presumed PDCCHs in TTIs with an UL direction.

FIG. 29 illustrates an example transmission of HARQ-ACK information fromUE 114 in response to detection or absence of detection by UE 114 of aPDCCH intended to a group of UEs where the HARQ-ACK information isincluded with other HARQ-ACK information transmitted from UE 114 inresponse to PDCCH detections associated with UE-specific DL schedulingaccording to this disclosure. The embodiment of the transmission shownin FIG. 29 is for illustration only. Other embodiments could be usedwithout departing from the scope of the present disclosure.

As shown in FIG. 29, UE 114 transmits HARQ-ACK information bits in aPUCCH in response to one or more detections by UE 114 of respectivePDCCHs scheduling respective PDSCH receptions to UE 114. UE 114 includesin the PUCCH a HARQ-ACK information bit having a value determined bywhether UE 114 detected UE 114-group common PDCCH 2910. UE 114 alsoincludes in the PUCCH one or more HARQ-ACK information bits in responseto receptions of PDSCHs 2920. Finally, UE 114 also can multiplex in thePUCCH other UCI, such as P-CSI or SR, if any 2930.

Although the previous realization of the third embodiment of thedisclosure considered that a HARQ-ACK information bit regarding adetection of a PDCCH transmitted from eNB 102 to a group of UEs istransmitted by UE 114 in a PUCCH that also conveys HARQ-ACK informationbits regarding receptions of PDSCHs, the HARQ-ACK information bit caninstead be transmitted by UE 114 in a PUCCH conveying only P-CSI and aresulting PUCCH format is referred to as PUCCH Format 2a (see also REF1). If UE 114 also conveys HARQ-ACK information bits regarding receptionoutcomes of PDSCHs, UE 114 can apply bundling to the HARQ-ACKinformation bits when UE 114 also transmits a HARQ-ACK information bitregarding a detection of a PDCCH transmitted from eNB 102 to a group ofUEs so that it transmits, together with the P-CSI, both types ofHARQ-ACK information using, respectively, a second bit and a first bitand a resulting PUCCH format is referred to as PUCCH Format 2b (see alsoREF 1).

Acknowledgement information from UE 114 regarding a detection of a PDCCHinforming of an adapted TDD UL-DL configuration can also be implicitwithout a direct transmission of HARQ-ACK information. As previouslydescribed, UE 114 operating with an adapted TDD UL-DL configuration isassumed to report two types of CSI; one for a first configured set ofTTIs, such as DL fixed TTIs and possibly some flexible DL TTIs andanother for a second configured set of TTIs, such as remaining DLflexible TTIs in an adapted TDD UL-DL configuration. This is neededbecause the interference conditions experienced by UE 114 can vary amongDL TTIs depending on whether or not an interfering cell uses that TTI asa DL one or as an UL one. When UE 114 fails to detect a PDCCH conveyinga DCI format informing of an adapted TDD UL-DL configuration, UE 114reverts to a conventional TDD UL-DL configuration (non-adapted) that canbe different than the adapted one. As UE 114 does not know the adaptedTDD UL-DL configuration, UE 114 cannot know of resources available formeasuring CSI in DL flexible TTIs (does not have a valid resource forCSI measurement in respective set of TTIs) and providing such a CSIreport to eNB 102 may not be useful as it is likely to be inaccurate andUE 114 anyway follows a conventional TDD UL-DL configuration where it isnot scheduled PDSCH transmissions in DL flexible TTIs. UE 114 cantherefore set the CSI report for a second set of TTIs to a predeterminedvalue, such as an Out-Of-Range (OOR) value. ENB 102 can then use thereported CSI value to determine whether or not UE 114 detected the PDCCHinforming of a respective adapted TDD UL-DL configuration.

Furthermore, when UE 114 is in DRX mode in DL TTIs where eNB 102transmits the PDCCH conveying the DCI format informing of an adapted TDDUL-DL configuration, eNB 102 knows that UE 114 fails to detect the DCIformat and UE 114 can skip the CSI transmission for the second set ofTTIs in order to conserve power and reduce interference.

Interpretation of a DCI Format Field as an UL Index Field or as an ULDAI Field

In certain embodiments, UE 114 configured for operation with an adaptedTDD UL-DL configuration and with TDD UL-DL configuration 0 for operationwith a non-adapted TDD UL-DL configuration, such as when UE 114 fails todetect a PDCCH informing of an adapted TDD UL-DL configuration, caninterpret a field in a DCI format scheduling a PUSCH as an UL DAI.Conversely, UE 114 that is not configured for operation with and adaptedTDD UL-DL configuration and operates with TDD UL-DL configuration 0always interprets a field in a DCI format scheduling a PUSCH as an ULindex.

For UE 114 configured for operation with an adapted TDD UL-DLconfiguration, using always a field as an UL DAI can result in arestriction that a PUSCH transmission can be scheduled only in a subsetof UL TTIs. However, this restriction may not have a material impact inan UL cell throughput as UEs that are not configured for operation withan adapted TDD UL-DL configuration can be scheduled in all UL TTIs.Moreover, as previously mentioned for UE 114 configured for operationwith an adapted TDD UL-DL configuration, an UL DAI is needed only in aDCI format scheduling a PUSCH when the PUSCH is transmitted in an UL TTIwhere UE 114 can transmit HARQ-ACK; when the PUSCH is transmitted in anUL TTI where UE 114 does not transmit HARQ-ACK, the UL DAI is not neededand the field can serve as an UL index when TDD UL-DL configuration 0 isthe conventional TDD UL-DL configuration.

If eNB 102 schedules a PUSCH transmission from UE 114 configured foroperation with an adapted TDD UL-DL configuration and eNB 102 expects UE114 to detect a PDCCH conveying a DCI format that indicates an adaptedTDD UL-DL configuration, eNB 102 can use a field in a DCI formatscheduling a PUSCH as UL index, at least in some TTIs, in case TDD UL-DLconfiguration 0 is the conventional one and as UL DAI in case any otherTDD UL-DL configuration is the conventional one. The interpretation ofthe UL DAI field is according to a reference TDD UL-DL configurationthat is configured to UE 114 for transmission of HARQ-ACK information.If eNB 102 does not expect UE 114 to detect the PDCCH, for example whenUE 114 is in DRX in DL TTIs of the PDCCH transmission, both eNB 102 andUE 114 know that UE 114 operates with the conventional TDD UL-DLconfiguration for the next validity period of an adaptation of a TDDUL-DL configuration. Then, if TDD UL-DL configuration 0 is theconventional one, the field can be assumed to function as an UL index inall TTIs (instead of functioning as an UL index only in the TTIs whereUE 114 does not transmit HARQ-ACK information). For UEs that are notconfigured for operation with an adapted TDD UL-DL configuration and donot operate with TDD UL-DL configuration 0, the field in always used asan UL DAI.

FIG. 30 illustrates an example interpretation of a field in a DCI formatscheduling a PUSCH either as an UL index or as an UL DAI for UE 114configured to operate with an adapted TDD UL-DL configuration and withTDD UL-DL configuration 0 as the conventional TDD UL-DL configurationaccording to this disclosure. While the flow chart depicts a series ofsequential steps, unless explicitly stated, no inference should be drawnfrom that sequence regarding specific order of performance, performanceof steps or portions thereof serially rather than concurrently or in anoverlapping manner, or performance of the steps depicted exclusivelywithout the occurrence of intervening or intermediate steps. The processdepicted in the example depicted is implemented by a transmitter chainin, for example, a mobile station.

As shown in FIG. 30, UE 114 configured for operation with an adapted TDDUL-DL configuration and can receive a PDCCH conveying a DCI formatindicating an adapted TDD UL-DL configuration, determines whether TDDUL-DL configuration 0 is the conventional TDD UL-DL configuration inoperation 3010. If it is, UE 114 interprets the field in a DCI formatscheduling a PUSCH as an UL index when the PUSCH transmission in an ULTTI where UE 114 does not transmit HARQ-ACK information and as an UL DAIwhen the PUSCH transmission is in an UL TTI where UE 114 can transmitHARQ-ACK information in operation 3020. If it is not, UE 114 interpretsa field in a DCI format scheduling a PUSCH as an UL DAI field inoperation 3030 when the PUSCH is transmitted in an UL TTI where UE 114can transmit HARQ-ACK information and as having a predetermined value,such as zero, when the PUSCH is transmitted in an UL TTI where UE 114does not transmit HARQ-ACK information.

Although the present disclosure has been described with an exemplaryembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

What is claimed is:
 1. A method for wireless communication, the methodcomprising: identifying a first set of two or more subframes within aframe and a second set of two or more subframes within the frame;receiving a first physical uplink control channel (PUCCH) resourceoffset to be used with the first set of subframes and a second PUCCHresource offset to be used with the second set of subframes; receivingdata in a first subframe within the frame; determining a PUCCH resourcefor a hybrid automatic repeat request acknowledgement (HARQ-ACK) signalbased on one of the first PUCCH resource offset and the second PUCCHresource offset, wherein the PUCCH resource for the HARQ-ACK signal isdetermined based on the first PUCCH resource offset when the firstsubframe belongs to the first set of subframes and the PUCCH resourcefor the HARQ-ACK signal is determined based on the second PUCCH resourceoffset when the first subframe belongs to the second set of subframes;and transmitting the HARQ-ACK signal using the determined PUCCHresource.
 2. A method for wireless communication, the method comprising:receiving a first physical uplink control channel (PUCCH) resourceoffset and a second PUCCH resource offset; identifying a first set ofsubframes and a second set of subframes; receiving data in a firstsubframe; determining a PUCCH resource for a hybrid automatic repeatrequest acknowledgement (HARQ-ACK) signal based on one of the firstPUCCH resource offset and the second PUCCH resource offset, wherein thePUCCH resource for the HARQ-ACK signal is determined based on the firstPUCCH resource offset when the first subframe belongs to the first setof subframes and the PUCCH resource for the HARQ-ACK signal isdetermined based on the second PUCCH resource offset when the firstsubframe belongs to the second set of subframes; and transmitting theHARQ-ACK signal using the determined PUCCH resource, wherein the firstPUCCH resource offset is received through system information block (SIB)signaling and the second PUCCH resource offset is received throughhigher layer signaling.
 3. The method of claim 1, wherein the first setof subframes comprises a subframe, and wherein a UL subframe forHARQ-ACK signal transmission associated with the subframe is the same asa UL subframe in a first UL/DL configuration.
 4. The method of claim 1,wherein the second set of subframes comprises a subframe, and wherein aUL subframe for HARQ-ACK signal transmission associated with thesubframe is different from a UL subframe in a first UL/DL configuration.5. The method of claim 4, wherein the first UL/DL configuration ispredetermined.
 6. A user equipment, the user equipment comprising:processing circuitry configured to identify a first set of two or moresubframes within a frame and a second set of two or more subframeswithin the frame; and a receiver configured to receive a first physicaluplink control channel (PUCCH) resource offset to be used with the firstset of subframes and a second PUCCH resource offset to be used with thesecond set of subframes, wherein the receiver is configured to receivedata in a first subframe within the frame, and wherein the processingcircuitry is configured to determine a PUCCH resource for a hybridautomatic repeat request acknowledgement (HARQ-ACK) signal based on oneof the first PUCCH resource offset and the second PUCCH resource offset,wherein the PUCCH resource for the HARQ-ACK signal is determined basedon the first PUCCH resource offset when the first subframe belongs tothe first set of subframes and the PUCCH resource for the HARQ-ACKsignal is determined based on the second PUCCH resource offset when thefirst subframe belongs to the second set of subframes; and a transmitterconfigured to transmit the HARQ-ACK signal using the determined PUCCHresource.
 7. The user equipment of claim 6, wherein the first PUCCHresource offset is received through system information block (SIB)signaling and the second PUCCH resource offset is received throughhigher layer signaling.
 8. The user equipment of claim 6, wherein thefirst set of subframes comprises a subframe, and wherein a UL subframefor HARQ-ACK signal transmission associated with the subframe is thesame as a UL subframe in a first UL/DL configuration.
 9. The userequipment of claim 6, wherein the second set of subframes comprises asubframe, and wherein a UL subframe for HARQ-ACK signal transmissionassociated with the subframe is different from a UL subframe in a firstUL/DL configuration.
 10. The user equipment of claim 9, wherein thefirst UL/DL configuration is predetermined.
 11. A method for wirelesscommunication, the method comprising: transmitting data in a firstsubframe within one of a first set of two or more subframes within aframe or a second set of two or more subframes within the frame;transmitting a first physical uplink control channel (PUCCH) resourceoffset to be used with the first set of subframes and a second PUCCHresource offset to be used with the second set of subframes; determininga PUCCH resource for a hybrid automatic repeat request acknowledgement(HARQ-ACK) signal based on one of the first PUCCH resource offset andthe second PUCCH resource offset, wherein the PUCCH resource for theHARQ-ACK signal is determined based on the first PUCCH resource offsetwhen the first subframe belongs to the first set of subframes and thePUCCH resource for the HARQ-ACK signal is determined based on the secondPUCCH resource offset when the first subframe belongs to the second setof subframes; and receiving the HARQ-ACK signal using the determinedPUCCH resource.
 12. The method of claim 11, wherein the first PUCCHresource offset is transmitted through system information block (SIB)signaling and the second PUCCH resource offset is received throughhigher layer signaling.
 13. The method of claim 11, wherein the firstset of subframes comprises a subframe, and wherein a UL subframe forHARQ-ACK signal transmission associated with the subframe is the same asa UL subframe in a first UL/DL configuration.
 14. The method of claim11, wherein the second set of subframes comprises a subframe, andwherein a UL subframe for HARQ-ACK signal transmission associated withthe subframe is different from a UL subframe in a first UL/DLconfiguration.
 15. The method of claim 14, wherein the first UL/DLconfiguration is predetermined.
 16. A base station, the base stationcomprising: a transmitter configured to transmit a first physical uplinkcontrol channel (PUCCH) resource offset and a second PUCCH resourceoffset, and data in a first subframe within one of a first set ofsubframes within a frame and a second set of subframes within the frame;a controller configured to determine a PUCCH resource for a hybridautomatic repeat request acknowledgement (HARQ-ACK) signal based on oneof the first PUCCH resource offset and the second PUCCH resource offset,wherein the PUCCH resource for the HARQ-ACK signal is determined basedon the first PUCCH resource offset when the first subframe belongs tothe first set of subframes and the PUCCH resource for the HARQ-ACKsignal is determined based on the second PUCCH resource offset when thefirst subframe belongs to the second set of subframes; and a receiverconfigured to receive the HARQ-ACK signal using the determined PUCCHresource.
 17. The base station of claim 16, wherein the first PUCCHresource offset is transmitted through system information block (SIB)signaling and the second PUCCH resource offset is transmitted throughhigher layer signaling.
 18. The base station of claim 16, wherein thefirst set of subframes comprises a subframe, and wherein a UL subframefor HARQ-ACK signal transmission associated with the subframe is thesame as a UL subframe in a first UL/DL configuration.
 19. The basestation of claim 16, wherein the second set of subframes comprises asubframe, and wherein a UL subframe for HARQ-ACK signal transmissionassociated with the subframe is different from a UL subframe in a firstUL/DL configuration.
 20. The base station of claim 19, wherein the firstUL/DL configuration is predetermined.